Patent Publication Number: US-9418148-B2

Title: System and method to label unlabeled data

Description:
BACKGROUND OF THE INVENTION 
     In a variety of different contexts, it is frequently necessary to discover classes and topics that data contains and to annotate data objects with those identified classes. For example, such annotation is useful for customer feedback forms, call center problem tickets and agent-customer conversational transcripts. 
     In the field of machine learning, there exist supervised and unsupervised techniques. However, supervised techniques require trained data and assume that the trained data is accurate; and, with unsupervised techniques, it is difficult to determine how to interpret clusters that are generated by such techniques. 
     SUMMARY OF THE INVENTION 
     In accordance with an embodiment of the invention, there is provided a device for labeling unlabeled data. The device comprises a clustering processor configured to group the unlabeled data to produce at least one data group; a feedback processor configured to enable a user to provide feedback on the at least one data group, the feedback including at least one of the following: (i) feedback on membership of a data object in a data group, and (ii) feedback on a current labeling of a data group; the clustering processor further configured to regroup the at least one data group using at least one constraint based on the feedback provided by the user; and the feedback processor further configured to apply a label to a data group of the at least one data group to produce at least one labeled data group, the label based on the feedback provided by the user after the grouping or on feedback provided by the user after at least one regrouping by the clustering processor. 
     In further, related embodiments, the feedback processor may be further configured to discover a set of data objects on which to seek feedback from the user; and the feedback processor may be still further configured to enable the user to provide feedback based on the discovered set of data objects. The clustering processor may comprise a K-means clustering processor, where the term K-means clustering is defined as partitioning n observations into k clusters in which each observation belongs to the cluster with the nearest mean. The feedback processor may be further configured to receive feedback provided by the user including at least one of the following: a new name of a data group; an acceptance of membership of a data object in a data group; a rejection of membership of a data object in a data group; a splitting of a data group; a merging of a data group; an acceptance of a member of a cluster centroid of a data group; and a rejection of a member of a cluster centroid of a data group. The feedback processor may be further configured to display at least one data object of the at least one labeled data group to the user. The clustering processor may be further configured to determine, for a data group of the at least one data group: (i) at least one data object belonging to the data group; and (ii) a context vector for the data group. The clustering processor may be further configured to determine, for a data group of the at least one data group, a scoring measure for the data group. The clustering processor may be further configured to group the data based on at least one initial constraint provided by the user. 
     In another embodiment according to the invention, there is provided a method for labeling unlabeled data. The method comprises grouping the unlabeled data using clustering to produce at least one data group; enabling a user to provide feedback on the at least one data group, the feedback including at least one of the following: (i) feedback on membership of a data object in a data group, and (ii) feedback on a current labeling of a data group; regrouping the at least one data group using further clustering including at least one constraint based on the feedback provided by the user; and applying a label to a data group to produce at least one labeled data group, the label based on the feedback provided by the user after the grouping or on feedback provided by the user after at least one regrouping. 
     In further, related embodiments, the method may further comprise discovering a set of data objects on which to seek feedback from the user. The enabling the user to provide feedback may be performed based on the discovered set of data objects. The grouping the data using clustering may comprise performing K-means clustering on the data. The feedback provided by the user may comprise at least one of the following: a new name of a data group; an acceptance of membership of a data object in a data group; a rejection of membership of a data object in a data group; a splitting of a data group; a merging of a data group; an acceptance of a member of a cluster centroid of a data group; and a rejection of a member of a cluster centroid of a data group. The method may further comprise displaying at least one data object of the at least one labeled data group to the user. Grouping the data may comprise, for a data group of the at least one data group, determining: (i) at least one data object belonging to the data group; and (ii) a context vector for the data group. Grouping the data may comprise, for a data group of the at least one data group, determining a scoring measure for the data group. The grouping the data using clustering may be performed based on at least one initial constraint provided by the user. 
     In another embodiment according to the invention, there is provided a non-transient computer-readable storage medium having computer-readable code stored thereon, which, when executed by a computer processor, causes the computer processor to label unlabeled data, by causing the processor to: group the unlabeled data using clustering to produce at least one data group; enable a user to provide feedback on the at least one data group, the feedback including at least one of the following: (i) feedback on membership of a data object in a data group, and (ii) feedback on a current labeling of a data group; regroup the at least one data group using further clustering including at least one constraint based on the feedback provided by the user; and apply a label to a data group to produce at least one labeled data group, the label based on the feedback provided by the user after the grouping or on feedback provided by the user after at least one regrouping. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The foregoing will be apparent from the following more particular description of example embodiments of the invention, as illustrated in the accompanying drawings in which like reference characters refer to the same parts throughout the different views. The drawings are not necessarily to scale, emphasis instead being placed upon illustrating embodiments of the present invention. 
         FIG. 1  is a block diagram of a device for labeling unlabeled data in accordance with an embodiment of the invention. 
         FIG. 2  is a block diagram of an example of an interaction model in which a user is enabled to provide feedback to a machine learning system, in accordance with an embodiment of the invention. 
         FIG. 3  is a diagram of components of an interactive framework for labeling the unlabeled data, in accordance with an embodiment of the invention. 
         FIGS. 4 through 9  are example interfaces for performing clustering in an interactive manner for discovering intents, in accordance with an embodiment of the invention. 
         FIG. 10  illustrates a computer network or similar digital processing environment in which an embodiment of the invention may be implemented. 
         FIG. 11  is a diagram of the internal structure of a computer (such as client processor/devices or server computers) in the computer system of  FIG. 10 , with which an embodiment of the invention may be implemented. 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     A description of example embodiments of the invention follows. 
     In accordance with an embodiment of the invention, there is provided a technique for permitting a machine to discover classes and topics that data contains and to annotate data objects with those identified classes. The technique enables machines to group and annotate data objects in ways that are meaningful and intuitive for a user of the data objects. 
     An embodiment according to the invention provides an interactive method that uses clustering, along with feedback from a user on the clustering output, to discover a set of classes. The feedback from the user is used to guide the clustering process in the later stages, which results in better and better discovery of classes and annotation with more and more human feedback. 
     A method in accordance with an embodiment of the invention can be used to produce labeled data that involves discovering classes and annotating a given dataset with the discovered class labels. This is advantageous for building a classifier that has wide applications, such as call routing and intent discovery. 
       FIG. 1  is a block diagram of a device for labeling unlabeled data in accordance with an embodiment of the invention. The device  100  includes a clustering processor  110  and a feedback processor  120 . Given a set of data points, the clustering processor  110  uses a clustering method to determine a grouping in the dataset. The clustering processor  110  outputs the clustering  115 , where each cluster is, for example, described based on the dominant features that appear in the cluster. The clustering output  115  is provided to the feedback processor  120 , which enables the user to see the objects that belong to each of the clusters and to provide feedback  125  on the clustering output. The feedback  125  from the user is then provided back to the clustering processor  110  in order to re-determine the clustering based on the new constraints provided by the user. 
       FIG. 2  is a block diagram  200  of an example of an interaction model in which a user is enabled to provide feedback to a machine learning system (such as a system that includes the device of  FIG. 1 ), in accordance with an embodiment of the invention. In the block diagram  200 , the system receives from a user a specified set of parameters for the clustering ( 201 ), which may be used as a set of constraints for an initial clustering. For example, the set of parameters may include a path of a data file, a number of clusters, use phrases or other parameters. The system performs the clustering and provides clustering output for each cluster ( 202 ); for example, the clustering output may be: a) the number of calls (or other data objects) in each cluster, a goodness measure for the cluster, and a context vector for the cluster; and b) all of the calls (or other data objects) belonging to the cluster sorted by belongingness. The system thereafter receives, from the user, feedback on the clustering ( 203 ). For example, the feedback may include enabling the user to name clusters, accept/reject members of a cluster, split/merge a cluster, and/or accept/reject words appearing in the context of a centroid of a cluster. The system then re-determines the constraints based on the feedback ( 204 ), and returns to re-perform the clustering based on the further constraints based on the feedback ( 202 ). Ultimately, after one or more iterations of this process, the system outputs a set of labeled data ( 205 ), which may include labels for one or more of the clusters, some or all of the data belonging to the cluster, and summary data for the clusters. For example, in addition to one or more labels for the clusters, the labeled data may include a) the number of calls (or other data objects) in each cluster, a goodness measure for the cluster, a best (or most-representative) member of the cluster, and a context vector for the cluster; and b) all of the calls (or other data objects) belonging to the cluster sorted by belongingness. 
     In another embodiment, the system can also prompt a user with some calls (or other data objects) that are the “best” calls for getting the feedback ( 203 ). One example of “best” calls is “representative calls” that have many other calls similar to them and therefore feedback on representative calls can easily and correctly be generalized to many other calls. 
       FIG. 3  provides an overview of the framework that uses interaction as described above for labeling the unlabeled data. Unlabeled data  330  is input to the interactive labeling framework  331 . The system performs grouping  332 , and may determine a set of “best” documents for feedback  333 . The grouping  332 , and, if determined, the “best” documents  333 , are provided to the user  334 . The user provides feedback  335 , based on which the system re-determines constraints for performing grouping  332  in a further iteration. Ultimately, after one or more iterations, the system outputs labeled data  336 , which includes one or more labeled clusters that have been produced based on the iterative process of: (i) machine clustering, followed by (ii) machine iteration of the clustering based on the user&#39;s input. 
       FIGS. 4 through 9  provide an example interface for performing clustering in an interactive manner for discovering intents, in accordance with an embodiment of the invention. 
     In  FIG. 4 , there is shown an example clustering output in accordance with an embodiment of the invention. Such an output may, for example, be produced by a feedback processor  120  based on output from clustering processor  110  for display to a user to receive feedback. The user is provided with an overall purity score  441  for the clustering, along with data for each of the clusters  442 - 444 , which here are shown before they have been labeled. Each cluster  442 - 444  has an individual score  445 - 447  indicating the tightness of that cluster. Further, each cluster  442 - 444  has a corresponding context vector  448 - 450 , indicating key words associated with each cluster. In addition, the user is provided with expansion tabs  451 - 453  to permit viewing of the underlying data points in each cluster. 
       FIG. 5  is a further example of clustering output in accordance with an embodiment of the invention. In this case, the underlying data  554 - 556  within a single cluster  543  has been expanded for display to a user to provide feedback. The underlying data  554 - 556  includes a transcription  557 - 559 , a file name  560 - 562 , a measure  563 - 565  of the data&#39;s belonging to the cluster, and an accept/reject input  566 - 568  for the user to choose whether each data point should be accepted or rejected from the cluster  543 . 
       FIG. 6  is a further example of clustering output in accordance with an embodiment of the invention. In this case, a user has provided a choice  666 ,  667  to accept two of the data points in the cluster. 
       FIG. 7  is a further example of clustering output in accordance with an embodiment of the invention. In this case, a user has provided a label  769  for the cluster, based on a review and interpretation of the content of the underlying data. 
       FIG. 8  is an example of providing membership constraints in accordance with an embodiment of the invention. In this case, the label  870  that was provided in  FIG. 7  has been applied to the cluster, and the user now provides accept/reject inputs  866 ,  867  which are used by the clustering processor as membership constraints in a subsequent iteration of the clustering. 
       FIG. 9  is an example of output from re-generating a clustering, in accordance with an embodiment of the invention. Two labels  970 ,  971  from previous user feedback have been associated with two of the clusters, which have been re-grouped based on constraints determined from the user&#39;s previous feedback. In this way, the data objects, which were initially unlabeled, have been grouped and annotated in ways that are meaningful and intuitive for a user of the data objects, based on both automated machine clustering and automated incorporation into the clustering of iterative feedback from the user. 
     An embodiment according to the invention may make use a variety of different possible methods of clustering. For example, K-means clustering may be used, where the term K-means clustering is defined as partitioning n observations into k clusters in which each observation belongs to the cluster with the nearest mean. A user may input a number of clusters to produce using K-means clustering. For example, techniques of clustering may be used such as those found in U.S. Pat. Nos. 6,460,035, 6,654,739 and 7,779,349, the teachings of which are hereby incorporated herein by reference in their entirety. Other techniques of clustering known in the art may be used, such as expectation-maximization clustering. 
     It will be appreciated that, in accordance with an embodiment of the invention, a user need not provide feedback on all underlying data or indeed on all clusters. 
     In accordance with an embodiment of the invention, constraints may be produced, added or changed based on the user&#39;s feedback, and are used in addition to the other constraints from previous iterations, which are kept intact. Based on the clustering methods that are used, data that is similar to user-accepted data in clusters is more likely to remain in a given cluster, whereas data that is similar to data that has been rejected from a cluster by a user is more likely to be removed from that cluster. Goodness measures for clusters may be measures of the tightness of the cluster, or any other scoring measures; and may be presented to the user along with other clustering data presented for user feedback. The system may discover the “best” data for user feedback, which may be documents that are most representative of groups of data, and prompt the user for feedback on that data. 
       FIG. 10  illustrates a computer network or similar digital processing environment in which the present invention may be implemented. Client computer(s)/devices  1081  and server computer(s)  1082  provide processing, storage, and input/output devices executing application programs and the like. Client computers  1081  can include, for example, the computers of users providing feedback on clustered data in accordance with an embodiment of the invention; and server computers  1082  can include the clustering processor  110 , feedback processor  120  and other systems implementing a technique for labeling unlabeled data in accordance with an embodiment of the invention. Client computer(s)/devices  1081  can also be linked through communications network  1083  to other computing devices, including other client devices/processes  1081  and server computer(s)  1082 . Communications network  1083  can be part of a remote access network, a global network (e.g., the Internet), a worldwide collection of computers, Local area or Wide area networks, and gateways that currently use respective protocols (TCP/IP, Bluetooth, etc.) to communicate with one another. Other electronic device/computer network architectures are suitable. 
       FIG. 11  is a diagram of the internal structure of a computer (e.g., client processor/device  1081  or server computers  1082 ) in the computer system of  FIG. 10 . Each computer  1081 ,  1082  contains system bus  1184 , where a bus is a set of hardware lines used for data transfer among the components of a computer or processing system. Bus  1184  is essentially a shared conduit that connects different elements of a computer system (e.g., processor, disk storage, memory, input/output ports, network ports, etc.) that enables the transfer of information between the elements. Attached to system bus  1184  is I/O device interface  1185  for connecting various input and output devices (e.g., keyboard, mouse, displays, printers, speakers, etc.) to the computer  1081 ,  1082 . Network interface  1186  allows the computer to connect to various other devices attached to a network (e.g., network  1083  of  FIG. 10 ). Memory  1187  provides volatile storage for computer software instructions  1188  and data  1189  used to implement an embodiment of the present invention (e.g., routines for implementing labeling of unlabeled data). Disk storage  1190  provides non-volatile storage for computer software instructions  1191  and data  1192  used to implement an embodiment of the present invention. Central processor unit  1193  is also attached to system bus  1184  and provides for the execution of computer instructions. 
     A system in accordance with the invention has been described in which unlabeled data is labeled. As used herein, a “clustering processor” is a portion of the system that groups data to produce at least one data group, and that re-groups the at least one data group using at least one constraint based on the feedback provided by a user. Such a clustering processor may, for example, be a portion of program code, operating on a computer processor. Further, as used herein, a “feedback processor” is a portion of the system that enables a user to provide feedback on at least one data group, for example feedback on membership of a data object in a data group and feedback on a current labeling of data group; and that applies a label to a data group of the at least one data group to produce at least one labeled data group, the label based on the feedback provided by the user after the grouping or on feedback provided by the user after at least one regrouping by the clustering processor. Such a feedback processor may, for example, be a portion of program code, operating on a computer processor. 
     Portions of the above-described embodiments of the present invention can be implemented using one or more computer systems, for example to permit labeling of unlabeled data. For example, the embodiments may be implemented using hardware, software or a combination thereof. When implemented in software, the software code can be executed on any suitable processor or collection of processors, whether provided in a single computer or distributed among multiple computers. 
     Further, it should be appreciated that a computer may be embodied in any of a number of forms, such as a rack-mounted computer, a desktop computer, a laptop computer, or a tablet computer. Additionally, a computer may be embedded in a device not generally regarded as a computer but with suitable processing capabilities, including a Personal Digital Assistant (PDA), a smart phone or any other suitable portable or fixed electronic device. 
     Also, a computer may have one or more input and output devices. These devices can be used, among other things, to present a user interface. Examples of output devices that can be used to provide a user interface include printers or display screens for visual presentation of output and speakers or other sound generating devices for audible presentation of output. Examples of input devices that can be used for a user interface include keyboards, and pointing devices, such as mice, touch pads, and digitizing tablets. As another example, a computer may receive input information through speech recognition or in other audible format. 
     Such computers may be interconnected by one or more networks in any suitable form, including as a local area network or a wide area network, such as an enterprise network or the Internet. Such networks may be based on any suitable technology and may operate according to any suitable protocol and may include wireless networks, wired networks or fiber optic networks. 
     Also, the various methods or processes outlined herein may be coded as software that is executable on one or more processors that employ any one of a variety of operating systems or platforms. Additionally, such software may be written using any of a number of suitable programming languages and/or programming or scripting tools, and also may be compiled as executable machine language code or intermediate code that is executed on a framework or virtual machine. 
     In this respect, at least a portion of the invention may be embodied as a computer readable medium (or multiple computer readable media) (e.g., a computer memory, one or more floppy discs, compact discs, optical discs, magnetic tapes, flash memories, circuit configurations in Field Programmable Gate Arrays or other semiconductor devices, or other tangible computer storage medium) encoded with one or more programs that, when executed on one or more computers or other processors, perform methods that implement the various embodiments of the invention discussed above. The computer readable medium or media can be transportable, such that the program or programs stored thereon can be loaded onto one or more different computers or other processors to implement various aspects of the present invention as discussed above. 
     In this respect, it should be appreciated that one implementation of the above-described embodiments comprises at least one computer-readable medium encoded with a computer program (e.g., a plurality of instructions), which, when executed on a processor, performs some or all of the above-discussed functions of these embodiments. As used herein, the term “computer-readable medium” encompasses only a computer-readable medium that can be considered to be a machine or a manufacture (i.e., article of manufacture). A computer-readable medium may be, for example, a tangible medium on which computer-readable information may be encoded or stored, a storage medium on which computer-readable information may be encoded or stored, and/or a non-transitory medium on which computer-readable information may be encoded or stored. Other non-exhaustive examples of computer-readable media include a computer memory (e.g., a ROM, a RAM, a flash memory, or other type of computer memory), a magnetic disc or tape, an optical disc, and/or other types of computer-readable media that can be considered to be a machine or a manufacture. 
     The terms “program” or “software” are used herein in a generic sense to refer to any type of computer code or set of computer-executable instructions that can be employed to program a computer or other processor to implement various aspects of the present invention as discussed above. Additionally, it should be appreciated that according to one aspect of this embodiment, one or more computer programs that when executed perform methods of the present invention need not reside on a single computer or processor, but may be distributed in a modular fashion amongst a number of different computers or processors to implement various aspects of the present invention. 
     Computer-executable instructions may be in many forms, such as program modules, executed by one or more computers or other devices. Generally, program modules include routines, programs, objects, components, data structures, etc. that perform particular tasks or implement particular abstract data types. Typically the functionality of the program modules may be combined or distributed as desired in various embodiments. 
     The teachings of all patents, published applications and references cited herein are incorporated by reference in their entirety. 
     While this invention has been particularly shown and described with references to example embodiments thereof, it will be understood by those skilled in the art that various changes in form and details may be made therein without departing from the scope of the invention encompassed by the appended claims.