Patent Publication Number: US-2013246413-A1

Title: Providing information prior to downloading resources

Description:
BACKGROUND 
     This specification relates to information presentation. 
     The Internet provides access to a wide variety of resources. For example, video and/or audio files, as well as web pages for particular subjects or particular news articles, are accessible over the Internet. 
     Some users employ mobile devices to access information on the Internet. In some circumstances, users may be sensitive to costs associated with access to Internet resources. For example, users that access Internet resources using a metered network (e.g., a mobile network having data rate charges or restrictions) may be less likely to access resources because of uncertainties in the cost. 
     SUMMARY 
     In general, one innovative aspect of the subject matter described in this specification can be implemented in methods that include a method for providing the search results. The method comprises receiving a query from a client device. The method further comprises responsive to the query, identifying, using one or more processors, search results including one or more resources. The method further comprises for at least one resource of search results, determining, using the one or more processors, a size of a data transfer required to access the one resource. The method further comprises providing the search results to the client device including providing a label associated with the one resource indicative of the size. 
     These and other implementations can each optionally include one or more of the following features. The label can include an estimate of the size based at least in part on historical data associated with the one resource. The label can include an estimate of the size based at least in part on prior loads of the one resource. The label can include an estimated size based at least in part on a retrieval of the one resource by a proxy prior to transmission of data associated with the one resource responsive to the query. The label can include a size estimate and a descriptor of a relative size of the transfer. The descriptor can include a slider ranging from small to large associated with the estimated size. The descriptor can reflect a particular category within a range of possible categories that are attributable based on the size estimate. The particular category can be a size selected from the group comprising small, medium, or large sized data. The descriptor can include a description of a category of resource. The category of resource can be a category selected from the group comprising video, images, audio, flash content, applications including embedded applications, rich content, fonts or scripts. The label can be a price associated with the data transfer. The price can be an amount that will be charged by a carrier for transferring the size of data in accordance with a data plan associated with a user of the client device. The price can include an indication of a current price that will be charged. The price can include an indication of a price that will be charged to load the data at a time in the future. The label can include plan usage data. The plan usage data can indicate an amount of data loaded in a given time period. The plan usage data can indicate an amount of remaining data that can be loaded in a given time period after loading the one resource. The method can further comprise determining a price charged by a delivery system associated with the client device that is used to present the one resource based at least in part on the size. Providing the search results to the client device can include providing the search results and label to a mobile device. Providing the search results to the client device can include providing the search results and the label to a tablet computing device. The label can be visible when the search results are provided. The label can be visible upon user selection of a hover control for the one resource. The label can be visible upon user selection of a link associated with the one resource, the label indicative of a size of a link resource associated with the link. The query can be a voice request. 
     In general, another innovative aspect of the subject matter described in this specification can be implemented in methods that include a method for providing labels including estimates of data transfer sizes. The method comprises receiving, through a browser, a request for loading a resource. The method further comprises, prior to loading the resource, determining, using one or more processors, a size of a data transfer to load the resource. The method further comprises presenting information, including a label, related to the size to the user prior to loading the resource. 
     These and other implementations can each optionally include one or more of the following features. The label can include an estimate of the size based at least in part on historical data associated with the resource. The label can include an estimate of the size based at least in part on prior loads of the resource. The label can include an estimated size based at least IN part on a retrieval of the resource by a proxy prior to transmission of data associated with the resource responsive to the request. The label can include a size estimate and a descriptor of a relative size of the transfer. The descriptor can include a slider ranging from small to large associated with the estimated size. The descriptor can reflect a particular category within a range of possible categories that are attributable based on the size estimate. The particular category can be a size selected from the group comprising small, medium, or large sized data. The descriptor can include a description of a category of resource. The category of resource can be a category selected from the group comprising video, images, audio, flash content, applications including embedded applications, rich content, fonts or scripts. The label can be a price associated with the data transfer. The price can be an amount that will be charged by a carrier for transferring the size of data in accordance with a data plan associated with a user of the client device. The price can include an indication of a current price that will be charged. The price can include an indication of a price that will be charged to load the data at a time in the future. The label can include plan usage data. The plan usage data can indicate an amount of data loaded in a given time period. The plan usage data can indicate an amount of remaining data that can be loaded in a given time period after loading the resource. The method can further comprise determining a price charged by a delivery system associated with the client device that is used to present the resource based at least in part on the size. Providing the search results to the client device can include providing the search results and label to a mobile device. Providing the search results to the client device can include providing the search results and the label to a tablet computing device. The request can be a voice request. 
     In general, another innovative aspect of the subject matter described in this specification can be implemented in methods that include a method for providing estimates of data transfer sizes. The method comprises receiving, at a proxy, a request for a resource from a client device. The method further comprises determining, using one or more processors, a size of a data transfer required to complete the request. The method further comprises providing, to the client device, an estimate of a size of a data transfer required to complete the request prior to exposing the client device to data charges resulting from transfer of data associated with the request. 
     These and other implementations can each optionally include one or more of the following features. Providing the estimate can include determining a size based at least in part on historical data. Providing the estimate can include determining a size based at least in part on data received from the resource when the proxy requests a load of the resource. Providing the estimate occurs prior to delivery of data associated with the resource to the client device. The method can further comprise passing the request from the proxy to the resource, receiving data from the resource responsive to the request, determining a size associated with one or more resources referenced in the received data, and providing size data associated with the one or more referenced resources along with the received data to the client device. The method can further comprise passing the request from the proxy to the resource, receiving data from the resource responsive to the request and determining a size of the data transfer from the resource based on the received data. 
     The details of one or more implementations of the subject matter described in this specification are set forth in the accompanying drawings and the description below. Other features, aspects, and advantages of the subject matter will become apparent from the description, the drawings, and the claims. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a block diagram of an example environment for delivering content. 
         FIG. 2A  is a block diagram of an example system for providing a label with a search result that indicates an estimated size of a data transfer of a corresponding resource. 
         FIG. 2B  shows an example presentation of a label that is presented after a resource is selected but before the resource is optionally loaded. 
         FIGS. 3A-3E  show example devices displaying search results that include transfer size labels of various kinds 
         FIG. 3F  shows an example user settings screen for specifying how transfer size labels are used. 
         FIG. 4A  is a flowchart of an example process for providing a label with a search result that indicates an estimated size of a data transfer of a corresponding resource. 
         FIG. 4B  is a flowchart of an example process for providing a label indicating an estimated transfer size of a resource after it is selected but before it is loaded. 
         FIG. 4C  is a flowchart of an example process in which a proxy provides an estimated size for a data transfer of a resource. 
         FIG. 5  is a block diagram of an example computer system that can be used to implement the methods, systems and processes described in this disclosure. 
     
    
    
     Like reference numbers and designations in the various drawings indicate like elements. 
     DETAILED DESCRIPTION 
     This document describes methods, processes and systems for providing information, including a label that identifies an estimated size and/or price associated with a data transfer of a resource. For example, if a user enters a search query on a mobile device (e.g., a cell phone, a tablet computing device, or some other device), the responsive search results can include size estimate labels. The labels, for example, can provide the user with a size estimate and/or a price estimate. The estimates can indicate to the user a relative size or cost associated with a transfer of data if the user selects the search result, thus causing the corresponding resource to be downloaded to the user&#39;s phone. Size estimates, for example, can be absolute (e.g., an actual numbers of bytes or bits), relative (e.g., “small,” “medium” or “large”), or presented in other ways. Price estimates can be based on the size estimates and may vary depending on the user&#39;s phone and/or data plan, the time of day, the location of the user, and other factors. Based on the information presented, the user may decide whether or not to select a particular search result, e.g., if downloading the corresponding resource is worth the estimated price (or is affordable by the user). Users can use the size estimate labels to control costs, e.g., down to the penny (or the user&#39;s local currency). 
     In some implementations, the size estimate labels may not be presented with the search results, but the information may be made available to the user automatically or upon user initiation. In some implementations, the user can use a control on the user device to prompt the display of the label information (e.g., the user may hover over the search result, and the corresponding size estimate label can be displayed). In some implementations, the user can select a particular search result, and instead of automatically downloading the resource, a size estimate label can be presented to the user. In this example, the user can make a choice, based on the displayed information, whether or not to proceed with the download. 
     While reference is made to search results, the information labels can be provided in other situations where data is attempted to be loaded in, for example, a metered data network. For example, the information label can be presented in conjunction with the selection of a resource on a page or with any request for data over the metered data network. In addition, an information label can be provided as part of the contents that are displayed to a user, where labels can be provided for each reference to a resource (e.g., a link on a page). 
     In some implementations, a sacheting system can be used, e.g., to remove financial uncertainty for the user. For example, a third party (e.g., a content provider) can guarantee that the estimated rates displayed to the user will be honored. The guaranteed rates can be realized by arranging with carriers to establish set rates for transmission to users associated with the carrier, e.g., to effectively bundle rates for large groups of users. 
     In some implementations, a spot market opportunity can be supported. For example, if a carrier&#39;s traffic is underutilized, estimates for traffic to be transferred over the network associated with the carrier can be lowered automatically, e.g., so as to encourage data transfers in the network. 
     While estimated sizes and prices mentioned herein are described using examples of data transfers in the form of downloads of resources, other data transfers are also within the scope of this disclosure. For example, the same or different sizes and prices can be associated with re-publishing content, such as if the user decides to share content with other users. In this example, the user can be presented with a label associated with re-publishing the content and can make the decision to re-publish or not based on the estimated price. 
     In some implementations, third-party sponsors can sponsor organic content page downloads that are free to the user, e.g., removing any financial concerns that the user may have about being able to afford the airtime or bandwidth costs of accessing the content over a metered network. For example, such organic content pages that are free for downloading by the user can be marked with a zero-cost label and/or highlighted in some other way. In some implementations, the third-party sponsors can target specific countries, user groups and/or content types. For example, a private foundation may be interested in sponsoring public health content to certain groups of people in Africa or other regions. 
       FIG. 1  is a block diagram of an example environment  100  for delivering content. The example environment  100  includes a content management system  110  for selecting and providing content in response to requests for content. The example environment  100  includes a network  102 , such as a local area network (LAN), a wide area network (WAN), the Internet, or a combination thereof. The network  102  connects websites  104 , user devices  106 , content sponsors  108  (e.g., advertisers), content publishers  109 , and the content management system  110 . The example environment  100  may include many thousands of websites  104 , user devices  106 , content sponsors  108  and content publishers  109 . 
     A website  104  includes one or more resources  105  associated with a domain name and hosted by one or more servers. An example website is a collection of web pages formatted in hypertext markup language (HTML) that can contain text, images, multimedia content, and programming elements, such as scripts. Each website  104  can be maintained by a content publisher, which is an entity that controls, manages and/or owns the website  104 . 
     A resource  105  can be any data that can be provided over the network  102 . A resource  105  can be identified by a resource address that is associated with the resource  105 . Resources include HTML pages, word processing documents, portable document format (PDF) documents, images, video, and news feed sources, to name only a few. The resources can include content, such as words, phrases, images, video and sounds, that may include embedded information (such as meta-information hyperlinks) and/or embedded instructions (such as JavaScript scripts). 
     A user device  106  is an electronic device that is under control of a user and is capable of requesting and receiving resources over the network  102 . Example user devices  106  include personal computers, mobile communication devices (e.g., smartphones and tablet devices), set-top boxes, television sets, and other devices that can send and receive data over the network  102 . A user device  106  typically includes one or more user applications, such as a web browser, to facilitate the sending and receiving of data over the network  102 . 
     A user device  106  can request resources  105  from a website  104 . In turn, data representing the resource  105  can be provided to the user device  106  for presentation by the user device  106 . The data representing the resource  105  can also include data specifying a portion of the resource or a portion of a user display, such as a presentation location of a pop-up window or a slot of a third-party content site or web page, in which content can be presented. These specified portions of the resource or user display are referred to as slots (e.g., ad slots). 
     To facilitate searching of these resources, the environment  100  can include a search system  112  that identifies the resources by crawling and indexing the resources provided by the content publishers on the websites  104 . Data about the resources can be indexed based on the resource to which the data corresponds. The indexed and, optionally, cached copies of the resources can be stored in an indexed cache  114 . 
     User devices  106  can submit search queries  116  to the search system  112  over the network  102 . In response, the search system  112  can, for example, access the indexed cache  114  to identify resources that are relevant to the search query  116 . The search system  112  identifies the resources in the form of search results  118  and returns the search results  118  to the user devices  106  in search results pages. A search result  118  is data generated by the search system  112  that identifies a resource that is responsive to a particular search query, and includes a link to the resource. In some implementations, the content management system  110  can generate search results  118  using information (e.g., identified resources) received from the search system  112 . An example search result  118  can include a web page title, a snippet of text or a portion of an image extracted from the web page, and the URL of the web page. As described above, the search results page can include, for example, additional information in the form of one or more labels related to a size and/or price associated with accessing a noted resource. Search results pages can also include one or more slots in which other content items (e.g., ads) can be presented. 
     In some implementations, the environment  100  can include plural data stores. For example, a data store of historical data  123  can store, for each resource  105  that has been downloaded within the environment  100 , the size of the resource (e.g., in bytes or bits). In some implementations, the size information can be stored each time a user selects a search result  118 , thereby initiating the download of the associated resource  105 . Because resources  105  can change over time in size and content, some implementations of the historical data  123  can store the size of the most recently-loaded version of the resource  105 , an average size of the last few downloads (e.g., the last 2-10), or some other representative size. 
     In some implementations, a data store of data plans  121  can include information about each user&#39;s rate information, which can include, for example, a price per N bytes of downloaded resources and/or air time. In some implementations, the data plans  121  can be assembled from information provided through partnerships or arrangements with various carriers or any other service providers that provide access to resources  105  by users. 
     In some implementations, the environment  100  can include a proxy system  130  that operates within a metered data network  140  to provide (and track the delivery of) content according to agreed-upon rates. The proxy system  130  can include plural engines. For example, a size engine  122  can determine an estimated size for a particular resource, e.g., by using past download size information for the resource in the historical data  123  or by loading the resource in real time. A price engine  124  can use the estimated size to determine an estimated price associated with the download. In some implementations, the price that is determined for each user can be based on information for that user in the data plans  121 . A label engine  126  can generate labels using size information from the size engine  122  and price information from the price engine  124 . In some implementations, if no size/price information is available, then the label engine  126  can generate a label that indicates uncertainty about the size and price. In some implementations, a message engine  128  can generate any needed messages that can, for example, be provided with price estimate labels that the user sees. 
     In some implementations, the proxy system  130 , including its plural engines, can use information from a delivery system  150  to provide labels. Example delivery systems  150  include phone, Internet and broadband providers and/or carriers. Using information provided by delivery systems  150 , for example, the price engine  124  can match an estimated size (e.g., determined by the size engine  122 ) with information from the user&#39;s data plan  121  to determine an estimated price of the download. In one example, if a user in Ghana has a data plan that charges one Ghana Cedi for a download of 100 kb or less, then the label for a 59 kb resource (e.g., estimated using historical information) can include corresponding and/or proportional size and price estimates (e.g., “59 kb. (about 1 GH¢ airtime)”). 
     For situations in which the systems discussed here collect or use personal information about users, the users may be provided with an opportunity to opt in/out of programs or features that may collect or use the personal information (e.g., information about a user&#39;s account). In addition, certain data may be anonymized in one or more ways before it is stored or used, so that personally identifiable information is removed. For example, a user&#39;s identity may be anonymized so that the no personally identifiable information can be determined for the user, or a user&#39;s geographic location may be generalized where location information is obtained (such as to a city, ZIP code, or state level), so that a particular location of a user cannot be determined. 
       FIG. 2A  is a block diagram of an example system  200  for providing a label with a search result that indicates an estimated size of a data transfer of a corresponding resource. For example, labels  204   a  and  204   b  can provide size information  206  for the data transfer of each resource associated with search results  118   a  and  118   b,  respectively. In some implementations, the size information  206  can include, for example, an estimated price (e.g., in the user&#39;s local currency) of a data download or access, an estimated size (e.g., in bits or bytes) of the corresponding resource, or some combination of price- and size-related information. The search results  118   a  and  118   b,  for example, can be provided to the user device  106  by the content management system  110  in response to the query  116 , as described above. 
     In some implementations, the estimate of the size and/or price can include determining a size based at least in part on historical data  123 . For example, if the resource associated with the search result  118   a  has in the past averaged 58 Mbytes of data, then the size engine  122  can use this information in estimating a size for any subsequent download. In some implementations, the price engine  124  can use the estimated size to determine an estimated price associated with the download. The label engine  126  can use either or both of the size and price estimates to generate the labels  204   a  and  204   b.    
     In some implementations, the proxy system  130 , including its components, can use information from the delivery system  150  to provide labels. For example, the price engine  124  can match an estimated size (e.g., determined by the size engine  122 ) with information from the user&#39;s data plan  121  to determine an estimated price of the download. 
     For example, labels  204   a  and  204   b  can provide size information  206  for the data transfer of each resource associated with search results  118   a  and  118   b,  respectively. In some implementations, the size information  206  can include, for example, an estimated price (e.g., in local currency) of a data download or access, an estimated size (e.g., in bits or bytes) of the corresponding resource, or some combination of price- and size-related information. The search results  118   a  and  118   b,  for example, can be provided to the user device  106  by the content management system  110  in response to the query  116 , as described above. 
     In some implementations, the message engine  128  can generate messages that can be provided with the size information  206  provided to the user. For example, if the user&#39;s data plan and current usage indicate that the user is approaching (or has exceeded) a threshold, then the message engine  128  can generate an informational message that is also displayable on the user device  106 . In some implementations, messages can be displayed in a search results area or can otherwise be available (e.g., as an additional alert icon that is displayed with the size information and that, when hovered over or selected, displays a message to the user). In some implementations, messages displayed to the user can identify the user&#39;s current charges and/or remaining data transfer capacity for a current time period. 
       FIG. 2B  shows an example presentation of a label  204   c  that is presented after a resource is selected but before the resource is optionally loaded. For example, search results  118   c  and  118   d,  when initially displayed on the user device  106 , may not include estimated size information. In some implementations, the size information (e.g., the label  204   c ) is presented after the user elects to load the resource (e.g., by clicking on or otherwise selecting the search result  118 ). In some implementations, a warning screen or prompt can be presented to the user in response to selection of a resource which includes the size/price information. Additional selection or default action/inaction may be required in order to initiate the load of the resource. In some implementations, the size information is presented if the user uses a control, such as a control that is activated when a cursor hovers over the search result  118   c.  Other controls are possible. For example, the size information can be presented, by including the label  204   c  in a popup  208 . Search result  118   d,  for example, shows an example search result for which the user has not yet selected the resource. 
       FIGS. 3A-3E  show example devices  106   a - 106   e  displaying search results  304  that include transfer size labels of various kinds. For example, referring to  FIG. 3A , search results  304   a - 304   c  (e.g., provided in response to a query  306 ) include labels  308   a - 308   c  corresponding to increasing data transfer sizes (e.g., 59, 172 and 1435 kb). In this example, the labels  308   a - 308   c  include size components  310   a - 310   c  and price components  312   a - 312   c , respectively. The price components  312   a - 312  in this example indicate an estimated price associated with the corresponding data transfer of the associated resource that the user can initiate (e.g., if the user believes the data transfer is worth the cost). 
     In some implementations, prices associated with downloading data can be displayed in a local currency. For example, if the user is currently located in Ghana (e.g., as determined from global positioning system (GPS) capabilities of the user device), then the price component  312   a  can indicate an estimated price of “about 1 GH¢ airtime” (e.g., expressed in Ghana Cedi). In some implementations, the currency or currencies in which estimated prices are displayed to the user can be a preferred currency of the user, the user&#39;s currency-of-record associated with a phone or data plan, or some user-configurable one or more currencies. Price estimates associated with the other search results  304   b  and  304   c  can be greater, e.g., “about 3 GH¢ airtime” for 172 kilobytes of data and “about 27 GH¢ airtime” for 1435 kilobytes of data. 
     Referring to  FIG. 3B , the information provided in price components  312   a - 312   c  is slightly different than the price components described with reference to  FIG. 3A . In this example, instead of using absolute price values (e.g., 1, 3 and 27 GH¢ of airtime), general descriptions or categories are used. For example, the price components  312   a - 312   c  can indicate that the expected prices associated the downloading the resources are categorized as “low,” “medium” or “high cost to download,” respectively. 
     In some implementations, the way in which the size components  310   a - 310   c  and the price components  312   a - 312   c  are presented can change (e.g., by using color-coding or other techniques) based on the relative size and/or price. For example, the size component  310   a  and the price component  312   a  for the smaller resources can be displayed in blue or green (e.g., indicating a smaller price), and increasingly hotter colors (e.g., shades of yellow and red) can be used to display size components and price components of increasingly larger resources. Color-coding such as described in this example can be used with other size components and price components described herein. Sizing or other means of emphasis of the information can also be used to reflect relative size/cost of the transfers. 
     Referring to  FIG. 3C , the information provided in price components  312   a - 312   c  is slightly different than the price components described with reference to  FIGS. 3A and 3B . For example, the price components  312   a - 312   c  in this example include bar graphics, where the length of the darkened area of the bar can indicate a relative expected size/price, e.g., substantially proportional to the size of the bar. In some implementations, color-coding can be used, e.g., by using cool colors (e.g., blues and greens) for the bars associated with smaller expected prices, and red for the bars associated with larger expected prices. In some implementations, the bar graphic can include label markings “small” and “large” to provide a measure of scale. 
     Referring to  FIG. 3D , price components  312   a - 312   c  include a download icon  314 . Other icons can be used. The price components  312   a - 312   c  in this example omit the bar graphics shown in  FIG. 3C  but still include general categories of small, medium and large. 
     Referring to  FIG. 3E , price components  312   a - 312   c  include coin symbols, where the number of coin symbols varies and is substantially proportional to estimated sizes/prices of the corresponding downloads. For example, the price components  312   a  associated with 59 kb includes one coin symbol, while the price components  312   b  and  312   c  (e.g., for larger estimated download sizes) include two and four coin symbols, respectively. Other symbols, icons or graphics can be used. In some implementations, the coin symbols can include abbreviations or other indicators of the user&#39;s local currently. In some implementations, in addition to the coin symbols, the actual estimated prices can also be shown. In some implementations, partial or fractional coin symbols can be used, e.g. to indicate fractions of GH¢ of airtime. In some implementations, the number of coin symbols can correspond to a geometric progression of prices, e.g., with one coin representing one GH¢, two coins representing N GH¢ (where N&gt;2), three coins representing N*N GH¢, and so on. In this example, hovering over the coin symbols can cause the actual price to be displayed. 
     While the examples in  FIGS. 3A-3E  show example labels that are displayed within search results, the same labels or different labels can be provided when a resource is selected or otherwise presented. For example, any of the labels or different labels can be presented when the user selects the search result or any presented resource, providing the user with an option to complete the data transfer after being presented with the associated size/price information. 
       FIG. 3F  shows an example user settings screen  330  for specifying how transfer size labels are used. For example, the user settings screen  330  can appear upon user selection of an option available on user device  106   f,  or at initial system start-up or initialization of a device. In some implementations, the user settings screen  330  can include an explanation  332  that describes how the transfer size labels work. For example, the explanation  332  can describe how the settings, based on user preferences, may affect whether and how labels such as the labels  308   a - 308   c  are to be displayed with search results or other presentations of resources or data transfer opportunities, as well as whether popups or other controls such as the popup  208  are used. 
     In some implementations, the user settings screen  330  can include a show settings area  334 , e.g., that includes check boxes, radio buttons or other controls for specifying when transfer size/price labels should appear. For example, a “Show transfer sizes with search results” option  336   a,  if selected, can enable the display of transfer size labels, such as the labels  308   a - 308   c  described above with reference to  FIG. 3A-3E . In another example, a “Do not show transfer sizes” option  336   b,  if selected, can disable the display of all transfer size labels. Other user-selectable options can also exist. 
     In some implementations, the user settings screen  330  can include a search results filter area  338 , e.g., that includes check boxes, radio buttons or other controls for specifying how search results are to be filtered based on the transfer size of the corresponding resources. For example, a “Show all web pages” option  340   a  can allow all search results to appear in the search results (e.g., search results  304 ) that are displayed in response to a query (e.g., the query  306 ). A user may select this setting, for example, to display all search results regardless of the estimated price of a data download if the user were to click on or otherwise select the search result. In some implementations, an “Only show small and medium pages” option  340   b  can allow the user to limit the search results to the less expensive estimated price related resources (e.g., preventing high-price pages). In some implementations, an “Only show small pages” option  340   c  can allow the user to limit search results that are shown to the least expensive category of expected prices. In some implementations, additional controls can be provided by which a user can specify an absolute monetary amount as the threshold amount, e.g., to prevent the display of search results for which downloading the resource would exceed that threshold amount. For example, a cost-conscious user in Ghana may set the threshold at 3 GH¢ to limit search results displayed to those having an estimated price of “about 3 GH¢ airtime” or less. In some implementations, informational controls such as a control  342 , if selected, can provide information to the user as to how the user settings are set and how they operate. 
     In some implementations, the user settings screen  330  can include additional controls. For example, a save control  344  can be selected by the user to save any settings and/or inputs made on the user settings screen  330 . A “Restore Default Settings” control  346  can be used to reset the checkboxes and other settings to a default value, e.g., that accompany the user device  106   f  upon initial receipt by the user. In some implementations, a “Select Display Currency . . . ” control  348  can be used to specify (e.g., using a list or a pop-up) the one or more currencies in which the user wishes to have labels  308   a - 308   c  displayed (e.g., in a local currency and/or currencies designated by the user). 
       FIG. 4A  is a flowchart of an example process  400  for providing a label with a search result that indicates an estimated size of a data transfer of a corresponding resource. The process  400  can be performed by the content management system  110  and/or the proxy system  130  (and/or its components).  FIGS. 1 ,  2 A and  3 A- 3 E are used to provide example structures for performing the steps of the process  400 . 
     A query is received from a client device ( 402 ). For example, the content management system  110  can receive the query  116  from any of the user devices  106   a - 106   e . The query can originate, for example, from a browser on a mobile user device (e.g., a cell phone, a tablet computing device, or some other device) operated by a user in a remote part of Africa (e.g., Ghana). 
     In some implementations, the query can be initiated by the user as a voice request. Other prompts for information can be manually or automatically activated. For example, a feature phone can include a rudimentary menu with predefined search categories (e.g., weather, scores, prices, etc.). When the user activates one of these menus, the application can conduct a request using the predefined information. The entire sequence of user selections and intermediate results can be price-labeled as well. For example, if the user&#39;s selection is a weather category, each weather-related option presented to the user can have an estimated size and price, such as an option to display today&#39;s forecast. Once that selection is made by the user, additional price-labeled options can be presented, such as along with the display of the current weather information for any other resource referenced on a page that includes the requested weather information. 
     In some implementations, the query can be initiated as a result of the user employing an interactive voice response (IVR) system. For example, the user in Africa can call into the IVR system and either navigate to pre-recorded information (e.g., weather, sports scores, etc.) or use a voice-driven system to ask a question or perform a search. The use of an IVR system can also have associated prices, e.g., prompting the user with the price before presenting the information. 
     Responsive to the query, search results are identified including one or more resources ( 404 ). As an example, the content management system  110  can provide the search results  304 . 
     For at least one resource of search results, a size of a data transfer required to access the one resource is determined ( 406 ). For example, the size engine  122  can determine an estimated size for the resource. Further, the price engine  124  can determine a corresponding estimated price, and the label engine  126  can generate a label indicative of the estimated size and/or estimated price. 
     The search results are provided to the client device including providing a label associated with the one resource indicative of the size/price ( 408 ). As an example, the search results  304   a - 304   c  can be provided to the any of the user devices  106   a - 106   e  (e.g., the user&#39;s mobile device in Africa), including the labels  308   a - 308   c.  As a result, the user in Ghana can see size and/or price estimates that apply to the potential data transfer (e.g., downloading of each of the resources) corresponding to the search results  304   a - 304   c.    
     The labels  308   a - 308   c  can include, for example, size estimates (e.g., size components  310   a - 310   c ) and a descriptor of a relative size of the transfer (e.g., the bar graphics and/or small/medium/large annotations described with reference to  FIGS. 3C-3D ). For example, the descriptor can include a slider ranging from small to large, where the position of the slider is associated with the estimated size. Each descriptor can reflect a particular category (e.g., small, medium, or large) within a range of possible categories that are attributable based on the size estimate. 
     In some implementations, descriptors can identify a category of resource associated with the search result, e.g., as a way for the user to gain knowledge of the type of resource that may contribute to its corresponding size. For example, the descriptor can identify the resource as including one or more of the categories of video, images, audio, flash content, applications including embedded applications, rich content, fonts and/or scripts. 
     In some implementations, the label includes an estimate of the size based at least in part on historical data associated with the one resource. For example, the size engine  122  can access historical data  123  to determine the size of the resource that was reported or recorded the last time (or previous times) that the resource was downloaded. In some implementations, size can include (or be an average of) multiple sizes corresponding to multiple downloads of the same resource. As a result, the label can include an estimate of the size based at least in part on prior loads of the one resource. 
     In some implementations, the label includes an estimated size based at least in part on a retrieval of the one resource by a proxy prior to transmission of data associated with the one resource responsive to the request. For example, instead of accessing information about prior loads of the resource, the proxy system  130  can retrieve the resource and determine its size (e.g., before the user elects to download the resource). 
     In some implementations, the label can include a price associated with the data transfer. For example, the price can be the price that the user in Africa would be charged by the user&#39;s phone carrier for transferring the size or amount of data in accordance with a user&#39;s data plan with the phone carrier. In some implementations, the price identified in the label can be the current price, e.g., for an immediate download of the resource. In some implementations, the price can include an indication of a price that will be charged to load the data at a future time. For example, the label that the user sees can identify a price for downloading the resource later, e.g., during off-peak hours or some other identified time. In some implementations, the label that is presented to the user can include plan usage data, e.g., indicating an amount of data loaded in a given time period (e.g., “You have loaded 987 kb of data so far this month, costing 32 GH¢ of airtime”). In some implementations, the label that is presented to the user can indicate an amount of remaining data that can be loaded in a given time period after loading the one resource (e.g., “If you load this resource, you will still have 17 GH¢ of airtime left for the month”). 
     In some implementations, the price associated with the data transfer can be the price charged by the delivery system  150  (e.g., the user&#39;s phone carrier) associated with the client device that is used to present the one resource based at least in part on the size. For example, the price that the user sees can be the price that will be charged under the user&#39;s data usage plan. 
     In some implementations, if the user selects a search result and the corresponding resource is downloaded, that resource can include multiple embedded links. In some implementations, each of the embedded links can be augmented to include a label that is visible, for example, upon user selection of a link associated with the resource. For example, after the user selects a link, the label that is displayed can indicate a size of a link resource associated with the link (e.g., including the cost of the user downloading the resource). 
       FIG. 4B  is a flowchart of an example process  420  for providing a label indicating an estimated transfer size of a resource after it is selected but before it is loaded. The process  420  can be performed by the content management system  110  and the proxy system  130  (and/or its components).  FIGS. 1 and 2B  are used to provide example structures for performing the steps of the process  420 . 
     A request is received through a browser for loading a resource ( 422 ). For example, referring to  FIG. 2B , the request can occur when the user selects the search result  118   c.  In some implementations, the request can be a voice request. For example, the request can be initiated as a result of the user employing an interactive voice response (IVR) system. For example, the user in Africa can call into the IVR system and either navigate to pre-recorded information (e.g., weather, sports scores, etc.) and make a selection of an option. 
     In some implementations, if the user is using a feature phone, the request can be a selection from a rudimentary menu with predefined search categories (e.g., weather, scores, prices, etc.). When the user activates one of the menu options, the application can initiate a request using the predefined information. 
     Prior to loading the resource, a size of a data transfer to load the resource is determined ( 424 ). As an example, the size engine  122  can determine an estimated size for the resource. Further, the price engine  124  can determine a corresponding estimated price, and the label engine  126  can generate a label indicative of the estimated size and/or estimated price. 
     Information that includes a label and is related to the size is presented to the user prior to loading the resource ( 426 ). As an example, referring to  FIG. 2B , the size information can be presented in a popup  208  using the label  204   c.  In some implementations, the label  204   c  can include, for example, size estimates and a descriptor of a relative size of the transfer (e.g., the bar graphics and/or small/medium/large annotations described with reference to  FIGS. 3C-3D ). For example, the descriptor can include a slider ranging from small to large, where the position of the slider is associated with the estimated size. Each descriptor can reflect a particular category (e.g., small, medium, or large) within a range of possible categories that are attributable based on the size estimate. In some implementations, descriptors can identify a category of resource associated with the search result, e.g., video, images, audio, flash content, applications including embedded applications, rich content, fonts and/or scripts. Other categories are possible. 
     In some implementations, the label includes an estimate of the size based at least in part on historical data associated with the one resource, e.g., as determined by the size engine  122  using historical data  123  corresponding to prior loads of the resource. In some implementations, the label includes an estimated size based at least in part on a retrieval of the one resource by a proxy prior to transmission of data associated with the one resource responsive to the request. For example, the proxy system  130  can retrieve the resource and determine its size in real time. 
     In some implementations, the label can include a price associated with the data transfer, such as the price that the user would be charged by the user&#39;s phone carrier for the data transfer, e.g., based on rates associated with the user&#39;s data plan. In some implementations, the price identified in the label can be the current price for an immediate download or a price that would be charged to load the data at a future time. In some implementations, the label that is presented to the user can include plan usage data, e.g., indicating an amount of data loaded in a given time period and/or an amount of remaining data that can be loaded in a given time period after loading the one resource. 
     In some implementations, the price associated with the data transfer can be the price charged by the delivery system  150  (e.g., the user&#39;s phone carrier). For example, the price that the user sees can be the price that will be charged under the user&#39;s data usage plan if the user downloads the resource. 
     In some implementations, if a search result is downloaded that includes one or more embedded links, each embedded link can include or be associated with a label that is visible, for example, upon user selection of a link. For example, after the user selects a link, the label that is displayed can indicate a size of a link resource associated with the link (e.g., including the cost of the user downloading the corresponding resource). 
       FIG. 4C  is a flowchart of an example process  440  in which a proxy provides an estimated size for a data transfer of a resource. For example, the process  440  can be used for resources associated with browsers (e.g., the cost of downloading resources associated with search results that are responsive to a query), email systems (e.g., the cost of downloading a full email message that corresponds to an email subject/header displayed in an inbox), or any other resource that can be transferred within a metered data network. The process  440  can be performed by the content management system  110  and the proxy system  130  (and/or its components).  FIGS. 1 and 2B  are used to provide example structures for performing the steps of the process  440 . 
     A request is received at a proxy for a resource from a client device ( 442 ). For example, referring to  FIG. 2B , the proxy system  130  (e.g., in combination with the content management system  110 ) can receive a request for the resource associated with the search result  118   c.    
     A size of a data transfer required to complete the request is determined ( 444 ). The size engine  122 , for example, can determine an estimated size of the resource, e.g., based at least in part on historical data  123 , as described above. 
     An estimate is provided to the client device that is an estimate of a size of a data transfer required to complete the request prior to exposing the client device to data charges resulting from transfer of data associated with the request ( 446 ). For example, the proxy system  130  (e.g., in combination with the content management system  110 ) can provide the estimated size to the user device  106 . 
     In some implementations, providing the estimate can include determining a size based at least in part on data received from the resource when the proxy requests a load of the resource. For example, the proxy system  130  can use information in the resource to determine an estimated size, e.g., by examining the resource&#39;s size using file size utilities or by determining the size by loading or pre-loading the resource. Providing the size estimate, for example, can occur prior to delivery of data associated with the resource to the client device. 
     In some implementations, the process  440  can further include additional operations of passing the request from the proxy to the resource; receiving data from the resource responsive to the request; determining a size associated with one or more resources referenced in the received data; and providing size data associated with the one or more referenced resources along with the received data to the client device. For example, the proxy system  130  can obtain and estimate size for the requested resource (e.g., web page A) then estimate the size of additional resources associated with any links in the resource (e.g., web pages X, Y and Z referenced by the web page A). The proxy system  130  can then provide four estimated sizes, one size for each of the web pages A, X, Y and Z. 
     In some implementations, the process  440  can further include additional operations of passing the request from the proxy to the resource; receiving data from the resource responsive to the request; and determining a size of the data transfer from the resource based on the received data. For example, the proxy system  130 , without obtaining the resource, can request of the resource to either identify its size or provide information by which the proxy system  130  can estimate its size. 
     As described above, data rate labels based on a size of the data transfer can be provided to a client device prior to the commencement of the download of the data. The price estimates provided in association with the data rate labels can be guaranteed by a service, such as the service that provides the price information. For example, a service can make an advance purchase of data bandwidth or a purchase guarantee with a carrier for a bulk volume of data bandwidth. The purchased data bandwidth can be resold with or without markup, such as to individual users on an a la carte basis. The service can accordingly pass on bulk pricing to the user, while allowing carriers to reduce uncertainty and risk regarding consumption volume, which can enhance their ability to forecast and plan for capacity increases and other capital expenditures. The service can provide solutions (e.g., software) to enable this inter-mediation, including allowing users to use their voice balance rather than maintain a separate voice and data balance. Forecasts of expected consumption can be made on a per user basis through user-specific models based on past individual and community consumption patterns. 
     One example of a method for providing the guaranteed cost delivery service includes receiving, by a processor, a request for data from an application on a metered data network. The request for data can be a request from a mobile handset for data from a resource that is transferred to the mobile device by a carrier. The user may have a contract with the carrier for voice or data services. In some implementations, the transaction contemplated herein includes a separate agreement with delivery service to engage in the bulk pricing. In some implementations, users can separately sign up for the delivery service. Some or all data transfers to/from the user device can be governed by the separate agreement. 
     Prior to transferring the data, the delivery service can determine a size of an associated data transfer to satisfy the request. The delivery system can, for example, do this as described above, such as by loading the data to a proxy or evaluating historical information associated with prior loads of the data. The delivery system can present information including price information to be charged by a carrier for transmission of the data based on the size. The price information can reflect an estimated cost to the user. 
     Upon receiving a confirmation to transfer the data, the price estimate can be honored by the delivery system. To facilitate such, the delivery system can estimate an aggregate amount of data that subscribers will consume in a time period, and establish a bulk price with the carrier for the aggregate amount. Honoring the estimate can include debiting a user&#39;s access plan associated with the carrier an amount equal to or less than the estimated price. 
     The application request can originate from an application executing on a mobile device. The metered data network can be a wireless network. The request for data can be a request from a browser for a resource. The price information can include an estimated cost in a local currency. 
     The access plan can be a voice plan and debiting the estimated price can include debiting an amount in a local currency against a balance kept in the local currency for voice communications in the metered data network. Alternatively the access plan can be of the form of a data plan or a combined voice and data plan. 
     Estimating an aggregate amount can include determining a first time period, determining a number of subscribers that have opted in to using bulk pricing, and estimating data usage by the number of subscribers in the first time period. 
     As described above, data rate labels can be provided at or in association with data requests received from, for example, a mobile device. In some implementations, a spot market can be created by the delivery system (where there conventionally is only a fixed market) for the delivery of data to consumers in the metered network. In some implementations, a capacity auction platform can be created to enable carriers to sell excess capacity at floating prices. The delivery system can use historical information about data consumption at price points to discern a single or group of user&#39;s individual price sensitivity curve. Using the price sensitivity curve information, the delivery system can determine, for example, price sensitive users and how specific changes in price at a specific time will drive changes in usage. A mechanism for surfacing these carrier offers can use data rate labels. Users will not need to submit a bid; instead, rate labels for price-sensitive users will automatically change (downward or upward), thereby embodying the offer from the carrier and stimulating or effectively pricing consumption. 
     In some implementations, the delivery system can provide tools for carriers, such as the ability to set a target utilization rate, or specific price bands for specific times of the day, to determine the carrier&#39;s offers. Based on these targets, the delivery system can adjust the data rate label price estimates in order to drive toward a targeted consumption goal for a given time period. 
       FIG. 5  is a block diagram of computing devices  500 ,  550  that may be used to implement the systems and methods described in this document, as either a client or as a server or plurality of servers. Computing device  500  is intended to represent various forms of digital computers, such as laptops, desktops, workstations, personal digital assistants, servers, blade servers, mainframes, and other appropriate computers. Computing device  550  is intended to represent various forms of mobile devices, such as personal digital assistants, cellular telephones, smartphones, tablet computing devices, and other similar computing devices. The components shown here, their connections and relationships, and their functions, are meant to be exemplary only, and are not meant to limit implementations of the inventions described and/or claimed in this document. 
     Computing device  500  includes a processor  502 , memory  504 , a storage device  506 , a high-speed interface  508  connecting to memory  504  and high-speed expansion ports  510 , and a low speed interface  512  connecting to low speed bus  514  and storage device  506 . Each of the components  502 ,  504 ,  506 ,  508 ,  510 , and  512 , are interconnected using various busses, and may be mounted on a common motherboard or in other manners as appropriate. The processor  502  can process instructions for execution within the computing device  500 , including instructions stored in the memory  504  or on the storage device  506  to display graphical information for a GUI on an external input/output device, such as display  516  coupled to high speed interface  508 . In other implementations, multiple processors and/or multiple buses may be used, as appropriate, along with multiple memories and types of memory. Also, multiple computing devices  500  may be connected, with each device providing portions of the necessary operations (e.g., as a server bank, a group of blade servers, or a multi-processor system). 
     The memory  504  stores information within the computing device  500 . In one implementation, the memory  504  is a computer-readable medium. In one implementation, the memory  504  is a volatile memory unit or units. In another implementation, the memory  504  is a non-volatile memory unit or units. 
     The storage device  506  is capable of providing mass storage for the computing device  500 . In one implementation, the storage device  506  is a computer-readable medium. In various different implementations, the storage device  506  may be a floppy disk device, a hard disk device, an optical disk device, or a tape device, a flash memory or other similar solid state memory device, or an array of devices, including devices in a storage area network or other configurations. In one implementation, a computer program product is tangibly embodied in an information carrier. The computer program product contains instructions that, when executed, perform one or more methods, such as those described above. The information carrier is a computer- or machine-readable medium, such as the memory  504 , the storage device  506 , or memory on processor  502 . 
     The high speed controller  508  manages bandwidth-intensive operations for the computing device  500 , while the low speed controller  512  manages lower bandwidth-intensive operations. Such allocation of duties is exemplary only. In one implementation, the high-speed controller  508  is coupled to memory  504 , display  516  (e.g., through a graphics processor or accelerator), and to high-speed expansion ports  510 , which may accept various expansion cards (not shown). In the implementation, low-speed controller  512  is coupled to storage device  506  and low-speed expansion port  514 . The low-speed expansion port, which may include various communication ports (e.g., USB, Bluetooth, Ethernet, wireless Ethernet) may be coupled to one or more input/output devices, such as a keyboard, a pointing device, a scanner, or a networking device such as a switch or router, e.g., through a network adapter. 
     The computing device  500  may be implemented in a number of different forms, as shown in the figure. For example, it may be implemented as a standard server  520 , or multiple times in a group of such servers. It may also be implemented as part of a rack server system  524 . In addition, it may be implemented in a personal computer such as a laptop computer  522 . Alternatively, components from computing device  500  may be combined with other components in a mobile device (not shown), such as device  550 . Each of such devices may contain one or more of computing device  500 ,  550 , and an entire system may be made up of multiple computing devices  500 ,  550  communicating with each other. 
     Computing device  550  includes a processor  552 , memory  564 , an input/output device such as a display  554 , a communication interface  566 , and a transceiver  568 , among other components. The device  550  may also be provided with a storage device, such as a microdrive or other device, to provide additional storage. Each of the components  550 ,  552 ,  564 ,  554 ,  566 , and  568 , are interconnected using various buses, and several of the components may be mounted on a common motherboard or in other manners as appropriate. 
     The processor  552  can process instructions for execution within the computing device  550 , including instructions stored in the memory  564 . The processor may also include separate analog and digital processors. The processor may provide, for example, for coordination of the other components of the device  550 , such as control of user interfaces, applications run by device  550 , and wireless communication by device  550 . 
     Processor  552  may communicate with a user through control interface  558  and display interface  556  coupled to a display  554 . The display  554  may be, for example, a TFT LCD display or an OLED display, or other appropriate display technology. The display interface  556  may comprise appropriate circuitry for driving the display  554  to present graphical and other information to a user. The control interface  558  may receive commands from a user and convert them for submission to the processor  552 . In addition, an external interface  562  may be provided in communication with processor  552 , so as to enable near area communication of device  550  with other devices. External interface  562  may provide, for example, for wired communication (e.g., via a docking procedure) or for wireless communication (e.g., via Bluetooth or other such technologies). 
     The memory  564  stores information within the computing device  550 . In one implementation, the memory  564  is a computer-readable medium. In one implementation, the memory  564  is a volatile memory unit or units. In another implementation, the memory  564  is a non-volatile memory unit or units. Expansion memory  574  may also be provided and connected to device  550  through expansion interface  572 , which may include, for example, a SIM card interface. Such expansion memory  574  may provide extra storage space for device  550 , or may also store applications or other information for device  550 . Specifically, expansion memory  574  may include instructions to carry out or supplement the processes described above, and may include secure information also. Thus, for example, expansion memory  574  may be provide as a security module for device  550 , and may be programmed with instructions that permit secure use of device  550 . In addition, secure applications may be provided via the SIM cards, along with additional information, such as placing identifying information on the SIM card in a non-hackable manner. 
     The memory may include for example, flash memory and/or MRAM memory, as discussed below. In one implementation, a computer program product is tangibly embodied in an information carrier. The computer program product contains instructions that, when executed, perform one or more methods, such as those described above. The information carrier is a computer- or machine-readable medium, such as the memory  564 , expansion memory  574 , or memory on processor  552 . 
     Device  550  may communicate wirelessly through communication interface  566 , which may include digital signal processing circuitry where necessary. Communication interface  566  may provide for communications under various modes or protocols, such as GSM voice calls, SMS, EMS, or MMS messaging, CDMA, TDMA, PDC, WCDMA, CDMA2000, or GPRS, among others. Such communication may occur, for example, through radio-frequency transceiver  568 . In addition, short-range communication may occur, such as using a Bluetooth, WiFi, or other such transceiver (not shown). In addition, GPS receiver module  570  may provide additional wireless data to device  550 , which may be used as appropriate by applications running on device  550 . 
     Device  550  may also communicate audibly using audio codec  560 , which may receive spoken information from a user and convert it to usable digital information. Audio codec  560  may likewise generate audible sound for a user, such as through a speaker, e.g., in a handset of device  550 . Such sound may include sound from voice telephone calls, may include recorded sound (e.g., voice messages, music files, etc.) and may also include sound generated by applications operating on device  550 . 
     The computing device  550  may be implemented in a number of different forms, as shown in the figure. For example, it may be implemented as a cellular telephone  580 . It may also be implemented as part of a smartphone  582 , personal digital assistant, tablet computing device, or other similar mobile device. 
     Various implementations of the systems and techniques described here can be realized in digital electronic circuitry, integrated circuitry, specially designed ASICs (application specific integrated circuits), computer hardware, firmware, software, and/or combinations thereof. These various implementations can include implementation in one or more computer programs that are executable and/or interpretable on a programmable system including at least one programmable processor, which may be special or general purpose, coupled to receive data and instructions from, and to transmit data and instructions to, a storage system, at least one input device, and at least one output device. 
     These computer programs (also known as programs, software, software applications or code) include machine instructions for a programmable processor, and can be implemented in a high-level procedural and/or object-oriented programming language, and/or in assembly/machine language. As used herein, the terms “machine-readable medium” “computer-readable medium” refers to any computer program product, apparatus and/or device (e.g., magnetic discs, optical disks, memory, Programmable Logic Devices (PLDs)) used to provide machine instructions and/or data to a programmable processor, including a machine-readable medium that receives machine instructions as a machine-readable signal. The term “machine-readable signal” refers to any signal used to provide machine instructions and/or data to a programmable processor. 
     To provide for interaction with a user, the systems and techniques described here can be implemented on a computer having a display device (e.g., a CRT (cathode ray tube) or LCD (liquid crystal display) monitor) for displaying information to the user and a keyboard and a pointing device (e.g., a mouse or a trackball) by which the user can provide input to the computer. Other kinds of devices can be used to provide for interaction with a user as well; for example, feedback provided to the user can be any form of sensory feedback (e.g., visual feedback, auditory feedback, or tactile feedback); and input from the user can be received in any form, including acoustic, speech, or tactile input. 
     The systems and techniques described here can be implemented in a computing system that includes a back end component (e.g., as a data server), or that includes a middleware component (e.g., an application server), or that includes a front end component (e.g., a client computer having a graphical user interface or a Web browser through which a user can interact with an implementation of the systems and techniques described here), or any combination of such back end, middleware, or front end components. The components of the system can be interconnected by any form or medium of digital data communication (e.g., a communication network). Examples of communication networks include a local area network (“LAN”), a wide area network (“WAN”), and the Internet. 
     The computing system can include clients and servers. A client and server are generally remote from each other and typically interact through a communication network. The relationship of client and server arises by virtue of computer programs running on the respective computers and having a client-server relationship to each other. 
     While this specification contains many specific implementation details, these should not be construed as limitations on the scope of any inventions or of what may be claimed, but rather as descriptions of features specific to particular implementations of particular inventions. Certain features that are described in this specification in the context of separate implementations can also be implemented in combination in a single implementation. Conversely, various features that are described in the context of a single implementation can also be implemented in multiple implementations separately or in any suitable subcombination. Moreover, although features may be described above as acting in certain combinations and even initially claimed as such, one or more features from a claimed combination can in some cases be excised from the combination, and the claimed combination may be directed to a subcombination or variation of a subcombination. 
     Similarly, while operations are depicted in the drawings in a particular order, this should not be understood as requiring that such operations be performed in the particular order shown or in sequential order, or that all illustrated operations be performed, to achieve desirable results. In certain circumstances, multitasking and parallel processing may be advantageous. Moreover, the separation of various system components in the implementations described above should not be understood as requiring such separation in all implementations, and it should be understood that the described program components and systems can generally be integrated together in a single software product or packaged into multiple software products. 
     Thus, particular implementations of the subject matter have been described. Other implementations are within the scope of the following claims. In some cases, the actions recited in the claims can be performed in a different order and still achieve desirable results. In addition, the processes depicted in the accompanying figures do not necessarily require the particular order shown, or sequential order, to achieve desirable results. In certain implementations, multitasking and parallel processing may be advantageous.