# Patent

## Title
Graph expansion mini-view

## Abstract

A graphical representation of a service model provides a full view of a portion of the graphical representation. A sub graph view may be displayed for nodes of the graphical representation of the service model that are associated with a selected node, including nodes that may not be visible in the full view. The sub graph view may be interactive, providing additional information regarding the nodes displayed in the sub graph view, and allowing making nodes in the sub graph view visible or invisible in the full view. Information may be displayed in the sub graph view about the status of the components being modeled by the service model corresponding to nodes displayed in the sub graph view.

## Background
CROSS REFERENCE TO RELATED APPLICATIONS
This application claims priority to U.S. Provisional Application Ser. No. 61/318,159 entitled “Graph Expansion Mini View” filed Mar. 26, 2010 and which is incorporated by reference in its entirety herein.


BACKGROUND
This disclosure relates generally to the field of management of information technology (IT) services. More particularly, but not by way of limitation, it relates to a technique for improving usability of IT service models.
Business Service Management (BSM) is a methodology of viewing technology infrastructure administration and problem diagnosis from the perspective of its impact on critical business services rather than technology silos. One aspect of BSM involves the development of service models that model the IT services of the enterprise, with component elements of the service model representing business users, services, and IT infrastructure components that provide the services, such as software and hardware components.
On a high level, a service model is a collection of components that represent a business service. A business service can have one or more business processes. Each business process can contain several functional applications, each of which can have multiple IT components. A service model will contain the processes, show how the components are interconnected, and show how component failures propagate and impact the upstream services.
Service models in today's IT environment are typically complex, containing potentially thousands of underlying dependent services and IT components. The representation of these services and IT components is typically done using directed acyclic graphs (DAGs), where each component of the service model, whether a business user, a service component, or an IT infrastructure component, is represented as a node in the graph. For big service models, however, the visualization aspect may become challenging for the user. On one hand, complex user interface (UI) components can be used to provide as much data as possible about the service model elements so that all information is available to the user without requiring too much screen switching. On the other hand, the complexity of the service models makes it difficult to present the most important data given the limited screen display area that is available.
Furthermore, graphs of complex service models can be very large and difficult to navigate and view. Expansion and contraction of branches can be especially tedious. A user looking at a collapsed node may have no knowledge of the size or complexity of the branches underneath a collapsed node and must manually open the sub-branches one level at a time. If there is a large set of sub-nodes, this can take many actions across many scrolling pages of view.
SUMMARY
A method is disclosed herein where users can get a concise preview sub graph view of the content above or below an object. In addition, this preview is interactive in that they can open and close nodes from within this mini-view.
In one embodiment, a method is disclosed. The method comprises displaying, in a first window, a first portion of a plurality of nodes, each of the plurality of nodes representing a component modeled by a service model; determining that a cursor is positioned substantially coincident with a first target area associated with a first node of the first portion of the plurality of nodes; displaying, in a second window, the first node and a second portion of the plurality of nodes coupled to the first node, at least some of the second portion of the plurality of nodes invisible in the first window, responsive to the act of determining that a cursor is positioned substantially coincident with a first target area associated with a first node of the first portion of the plurality of nodes; and ceasing display of the second window upon determining that the cursor is positioned outside of the second window.
In another embodiment, a system is disclosed. The system comprises: a processor; a display, coupled to the processor; a user input device, coupled to the processor; a storage subsystem, coupled to the processor; and software stored on the storage subsystem, that when executed causes the processor to perform acts comprising: generating a graphical representation of a service model, comprising a plurality of nodes, each representing a component modeled by the service model; displaying in a first window on the display a first portion of the plurality of nodes; defining a first target area on the display associated with a first node of the plurality of nodes; and displaying in a second window on the display the first node and a second portion of the plurality of nodes coupled to the first node, the second portion of the plurality of nodes mutually exclusive with the first portion of the plurality of nodes, responsive to detecting that a cursor associated with the user input device is positioned with the first target area.
In yet another embodiment, a computer readable medium is disclosed. The computer readable medium has stored thereon instructions that cause a programmable control device to perform the method described above.
In yet another embodiment, a networked computer system is disclosed. The networked computer system comprises a plurality of computers communicatively coupled, at least one of the plurality of computers programmed to perform at least a portion of the method described above wherein the entire method described above is performed collectively by the plurality of computers.



BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 illustrates, in graph form, an example of a service model graph according to the prior art.
FIG. 2 illustrates, in block diagram form, an embodiment of a graphical mini-view according to one embodiment.
FIG. 3 illustrates, in block diagram form, an embodiment of a graphical mini-view according to one embodiment.
FIG. 4 illustrates, in block diagram form, an embodiment of a graphical mini-view according to one embodiment, illustrating interactivity with the mini-view.
FIG. 5 illustrates, in block diagram form, an example of three alternative embodiments of a mini-view.
FIG. 6 illustrates, in block diagram form, a network of computing devices according to one embodiment of a system incorporating graphical mini-views.
FIG. 7 illustrates, in block diagram form, a computing device for generating and displaying graphical mini-views according to one embodiment.



DETAILED DESCRIPTION
In the following description, for purposes of explanation, numerous specific details are set forth in order to provide a thorough understanding of the invention. It will be apparent, however, to one skilled in the art that the invention may be practiced without these specific details. In other instances, structure and devices are shown in block diagram form in order to avoid obscuring the invention. References to numbers without subscripts are understood to reference all instance of subscripts corresponding to the referenced number. Moreover, the language used in this disclosure has been principally selected for readability and instructional purposes, and may not have been selected to delineate or circumscribe the inventive subject matter, resort to the claims being necessary to determine such inventive subject matter. Reference in the specification to “one embodiment” or to “an embodiment” means that a particular feature, structure, or characteristic described in connection with the embodiments is included in at least one embodiment of the invention, and multiple references to “one embodiment” or “an embodiment” should not be understood as necessarily all referring to the same embodiment.
The graphical elements of the embodiments illustrated in the figures are illustrative and by way of example only. Service model graphs may use any convenient or desired technique known to the art for displaying elements of a graph.
FIG. 1 is an example of a generic service model graph 100 according to the prior art with business users, services, and IT structure layers. The lines between the component instances represent the provider/consumer relationships. In this example, the service model graph 100 represents an organization 110 with user groups 120, services 130, and numerous IT components, in this example including a web server 140, applications 145, databases 150, an application server 155, database servers 160, and workstations 165. In actual service models, the service model graph 100 may include thousands or tens of thousands of elements, and a full-sized view of the service model graph 100 may be collapsible so that a single visible node in the service model graph 100 may represent a collapsed view of a portion of the service model graph 100 containing multiple components or sub-nodes that are collapsed into a single node for ease of use and display of the service model graph 100.
The nodes of the full-sized view of the service model graph 100 may be collapsed into nodes that represent multi-sub-node portions of the service model graph 100, in a form that may be expanded as desired by a user of the service model graph 100. But the use of collapsed nodes may present usability issues. A collapsed node provides no visible information about the size or complexity of the branches collapsed into it, and a user typically must manually open the sub-branches one level at a time. If there is a large set of sub-nodes this can take many actions across many scrolling pages of the full-sized view, and expanding the sub-node may explode the graph in unexpected ways.
FIG. 2 is a block diagram illustrating a technique for providing a graphical mini-view according to one embodiment. Node 200 is an example of a collapsed node of a full-sized view of a service model graph, where multiple sub-nodes of the service model graph have been collapsed into the node 200. For clarity, only node 200 is illustrated in FIG. 2, and the remainder of the view of the service model graph is omitted. Node 200 is represented by an icon that includes elements 210 and 220, in FIG. 2 illustrated as triangles or arrows pointing up and down relative to the node 200.
Elements 210 and 220 may be implemented as mouseover targets. Although represented in FIG. 2 as triangles or arrows, the mouseover targets may be any type of mouseover target areas or features on graphical display that may be activated when software detects that a user has moved a pointer or cursor over the mouseover area. Although the mouseover area typically includes a graphical element that encourages a user to position the pointer over the mouseover target area, in some embodiments, mouseover target areas may be used with no visible element.
In this embodiment, each node in the full-sized view of the service model graph has one or more mouseover target areas, depending upon the connectivity of the node represented in collapsed form to other nodes in the graph that have been collapsed into the collapsed node. For example, if the collapsed node represents one or more sub-nodes that would be displayed below the collapsed node on the graph when expanded, then a mouseover target area may be placed on the collapsed node in a lower portion of the collapsed node's visual display. Similarly, if the collapsed node represents one or more sub-nodes that would be displayed above the collapsed node on the graph when expanded, then a mouseover target area may be placed on the collapsed node in a upper portion of the collapsed node's visual display. A collapsed node that represents one or more sub-nodes that would be displayed above the collapsed node and below the collapsed node on the graph when expanded may have both an upper and lower mouseover target area placed on the collapsed node.
When the software detects that a user has positioned a cursor, such as a mouse pointer, substantially coincident with one of the mouseover target areas, a mini-view of at least some of the nodes collapsed into the collapsed node may be displayed. As illustrated in FIG. 2, positioning a cursor over the upper mouseover target area 210 may result in a mini-view 230, concisely representing some or all of the nodes rooted to node 200 that would be displayed in the service model graph (typically above the node 200 in the full-sized view) if the collapsed node 200 were expanded. Similarly, positioning a cursor over the lower mouseover target area 220 may result in a mini-view 240, concisely representing some or all of the nodes rooted from the node 200 that would be displayed in the service model graph (typically below the node 200 in the full-sized view) if the collapsed node 200 were expanded.
In the example mini-views 230 and 240 illustrated in FIG. 2, the collapsed node 200 is visible in the mini-view and is identified in FIG. 2 using the same visual characteristics as the collapsed node 200 to help identify the collapsed node 200 in the mini-view 230 or 240.
Mini-views 230 and 240 allow users to see a preview of the other nodes related to the node 200. The mini-views 230 and 240 may be displayed on top of the existing display of the service model graph.
In one embodiment, presentation of the mini-view automatically positions the cursor within the mini-view. When software detects that the user has moved the cursor away from mouseover target area 210 or 220, then mini-views 230 or 240 may automatically disappear or be removed from the display. Although described herein as mouseover targets, the techniques disclosed herein are compatible with all conventional graphical user interface (GUI) object selection techniques, such as single click, double-click, gestures, etc. In embodiments in which an object selection technique such as single click is used, a first object selection may cause the display of the mini-view and a second object selection may cause the mini-view to disappear.
Mini-views such as the example in FIG. 2 are unlike scrolling windows that have been used solely for scrolling purposes. A scrolling window is for scrolling around a view and does not provide for expansion and contraction or collapse of nodes in a graph view. Furthermore, unlike a scrolling window, the disclosed mini-views are associated with a selected object, not an entire graph or regional graph view, advantageously focusing the user just on the related nodes of current interest to the user. In addition, scrolling windows typically only allow scrolling around the current view of a graph, and do not allow display in the mini-view of objects that are currently hidden in the full-sized view, while the disclosed mini-views show objects that are related to the selected node, regardless of their visibility in the full-sized graph.
Disclosed embodiments of mini-views also provide capability unlike that found in magnifiers, which merely enlarge the visible view of a portion of the display. Various disclosed embodiments provide for interactions with the mini-view to perform actions on the nodes displayed in the mini-view, as described in more detail below.
FIG. 3 illustrates an embodiment in which moving the cursor over either of the mouseover target areas 210 or 220 results in a mini-view 300 that displays a combination of the mini-views 230 and 240, previewing related nodes to node 200 that rooted to or rooted from 200 in the full-size graph. In such an embodiment, the mouseover target area of the node 200 may be coextensive with the visual display of the collapsed node 200, so that positioning the cursor anywhere over the node 200 may cause the generation of the mini-view 300, instead of the separate upper and lower mouseover target areas illustrated in FIG. 2 and FIG. 3.
In one embodiment, the mouseover behavior may be optionally configured to behave as illustrated in either FIG. 2 or FIG. 3.
The related nodes made visible in the mini-view may be represented in a variety of representational ways with a variety of information about each node in the mini-view, as discussed in more detail below.
In one embodiment, the mini-view may be interactive. For example, users may select in the mini-view which related nodes they want to open or collapse within the full-sized view, using any standard GUI object selection technique known to the art. In one embodiment, the mini-view window or frame may be limited to a size insufficient to display all of the related nodes. In such an embodiment, the mini-view contents may be scrollable using any conventional scrolling technique known to the art.
In one embodiment, selecting a single node in the mini-view expands the branch of the full-size service model graph from the node 200 all the way out to the child node that was selected. In one embodiment, multiple nodes may be selected using any conventional multi-selection technique, allowing expanding multiple branches of the graph related to the node 200 with a single action. As illustrated in FIGS. 2 and 3, the mini-views 230, 240, and 300 may contain selection areas 250 and 260 that can be used to expand or collapse in the full-size graph all nodes shown in the mini-view.
In one embodiment, the node 200 may be any node of the service model graph, regardless of whether the node 200 is a collapsed node. The mini-view may then show nodes related to the node 200, regardless of whether those nodes are visible in the service model graph, allowing a convenient way to collapse or expand multiple nodes graphically related to the node 200.
In one embodiment, an option may control the number of levels of the service model graph that may be displayed in the mini-view. For example, in one embodiment, by default up to three levels of the graph may be displayed in the mini-views 230, 240, or 300, but a user may optionally select any desired number of levels for display in the mini-view.
In one embodiment, an option may control the screen display size of the mini-view using any technique for controlling the size of a frame or window. The mini-view may be automatically sized by default to fit the contents that are to be displayed in the mini-view. A user may also have the ability to interactively resize or move the mini-view window on the display using conventional window movement and resizing techniques.
As discussed above, in one embodiment, an option may control whether mouseover on an mouseover target opens just branches corresponding to that specific target (210 or 220) or for both targets 210 and 220. In one embodiment, the behavior on mouseover may vary depending on whether any branches are open related to the node 200. For example, if the node 200 is completely closed, with no branches in the service model graph connecting the node 200 to any other node, then a mouseover of either mouseover target may act as a mouseover event for both mouseover targets 210 and 220. If the node 200 has been expanded to display branches above or below the node 200, then a mouseover of a mouseover target corresponding to already open branches may have no effect, but a mouseover of a mouseover target corresponding to a side with no open branches may open a mini-view to display the branches that might be opened on that side of the node 200.
In some embodiments, the mouseover targets may be defined to correspond to selection targets of the node 200, so that a mouseover of the target produces a mini-view that corresponds to a portion of the service model graph that might be opened by a selection of the same target by a single click or other technique.
FIG. 4 illustrates an interaction with a mini-view 300 according to one embodiment. In this embodiment, a user may select one or more nodes displayed in the mini-view 300 to expand in the full-sized service model display. Thus, the nodes 400 selected by the user in the mini-view 300, as indicated by the shading, are expanded as nodes 410 in the full size graph of which node 200 is a part. This allows the user to display the mini-view 300 and then to choose which parts of the collapsed node 200 the user wishes to see in greater detail in the full-sized service model display, without having to expand separately each branch connected to the collapsed node 200. Alternately, the user may select either the “collapse all” selection area 250 or the “expand all” selection area 260 to collapse or expand all of the nodes displayed in the mini-view 300 in a single interaction.
FIG. 5 illustrates three alternative embodiments of techniques for displaying the nodes in the mini-views. In mini-view 500, the nodes are displayed as simple blocks. In mini-view 510, the nodes may be represented by icons based on their corresponding object type. In mini-view 520, the nodes may be colored corresponding to the status of the corresponding element in the service model. These display techniques are illustrative and by way of example only and other display techniques may be used, including combinations, such as representing nodes by object type icons that are colored according to the element's status. In one embodiment, the node corresponding to node 200 may be identified in the mini-views 500, 510, or 520 by highlighting, shading, coloring, or any other convenient or desired technique for differentiating one node in a graph.
Mini-views such as illustrated in FIGS. 2-5 may be interactive, with the mouseover targets available in the mini-view that may respond to mouseover events with additional windows or frames that may contain additional information about the node or nodes related to the mouseover events. For example, in one embodiment, positioning a mouse pointer over one of the nodes in the mini-view may generate a window that provides detailed information about the corresponding mini-view node.
FIG. 6 is a block diagram illustrating an IT infrastructure 600 that may include elements that provide access to service model graphs that incorporate mini-view as disclosed above. A user 610 may use a terminal or workstation to access service model graph software to display a service model graph such as illustrated in FIG. 1 on a display associated with the workstation. The software generating the graphical display of the service model graph on the user 610 workstation display, including the mini-views, may execute on the workstation for the user 610 or on other computing resources of the IT infrastructure 600, such as a mainframe 620, a web server 660, a database server 630, an application server 655, and other workstations 640, laptops 635. The IT infrastructure 600 may include one or more databases 625 that store data related to the service model graph corresponding to the organizational elements, services, IT hardware, and IT software that is modeled by the service model. The IT infrastructure may further include other IT resources, such as a printer 645. The IT infrastructure may be connected in any way known to the art, including using switches or routers 615 and networks 650.
Referring now to FIG. 7, an example computer 700 for use in providing a mini-view display is illustrated in block diagram form. Example computer 700 comprises a system unit 710 which may be optionally connected to an input device or system 760 (e.g., keyboard, mouse, touch screen, etc.) and display 770. A program storage device (PSD) 780 (sometimes referred to as a hard disc) is included with the system unit 710. Also included with system unit 710 is a network interface 740 for communication via a network with other computing and corporate infrastructure devices such as are shown in FIG. 6. Network interface 740 may be included within system unit 710 or be external to system unit 710. In either case, system unit 710 will be communicatively coupled to network interface 740. Program storage device 780 represents any form of non-volatile storage including, but not limited to, all forms of optical and magnetic, including solid-state, storage elements, including removable media, and may be included within system unit 710 or be external to system unit 710. Program storage device 780 may be used for storage of software to control system unit 710, data for use by the computer 700, or both.
System unit 710 may be programmed to perform methods in accordance with this disclosure. System unit 710 comprises a processor unit (PU) 720, input-output (I/O) interface 750 and memory 730. Processing unit 720 may include any programmable controller device including, for example, one or more members of the Intel Atom®, Core®, Pentium® and Celeron® processor families from Intel Corporation and the Cortex and ARM processor families from ARM. (INTEL, INTEL ATOM, CORE, PENTIUM, and CELERON are registered trademarks of the Intel Corporation. CORTEX is a registered trademark of the ARM Limited Corporation. ARM is a registered trademark of the ARM Limited Company.) Memory 730 may include one or more memory modules and comprise random access memory (RAM), read only memory (ROM), programmable read only memory (PROM), programmable read-write memory, and solid-state memory. One of ordinary skill in the art will also recognize that PU 720 may also include some internal memory including, for example, cache memory.
It is to be understood that the above description is intended to be illustrative, and not restrictive. For example, the above-described embodiments may be used in combination with each other. Many other embodiments will be apparent to those of skill in the art upon reviewing the above description. The scope of the invention therefore should be determined with reference to the appended claims, along with the full scope of equivalents to which such claims are entitled. In the appended claims, the terms “including” and “in which” are used as the plain-English equivalents of the respective terms “comprising” and “wherein.”

## Claims

1. A method, comprising:
displaying, in a first window, a first portion of a plurality of nodes, each of the plurality of nodes representing one or more components modeled by a service model, the first portion including a first node of the first portion of the plurality of nodes, the first node representing multiple subnodes of the service model not displayed in the first window and the first window including a representation of the first node with an associated first target area and an associated second target area;
displaying a second window in response to determining that a cursor is positioned substantially coincident with the first target area, the second window displaying the first node coupled with at least some of the subnodes of the service model represented by the first node, the subnodes displayed in the second window being a second portion of the plurality of nodes that are absent from the first window; and
displaying a third window in response to determining that the cursor is positioned substantially coincident with the second target area, the third window displaying the first node coupled with at least some of the subnodes of the service model represented by the first node, the subnodes displayed in the third window being a third portion of the plurality of nodes that are absent from the first window, wherein the third portion is disjoint from the second portion.

2. The method of claim 1, wherein displaying the first node coupled with the second portion of the plurality of nodes comprises:
displaying a second node of the second portion of the plurality of nodes in a color indicating a status of a component corresponding to the second node.

3. The method of claim 1, wherein displaying the first node coupled with the second portion of the plurality of nodes comprises:
displaying a second node of the second portion of the plurality of nodes as an icon representing a type of the component corresponding to the second node.

4. The method of claim 3, wherein displaying the second node of the second portion of the plurality of nodes as the icon representing the type of the component corresponding to the second node comprises:
displaying the icon in a color indicating a status of the component corresponding to the second node.

5. The method of claim 1, further comprising:
detecting a selection of a second node of the second portion of the plurality of nodes; and
displaying the second node connected to the first node in the first window, wherein nodes in the second portion not in a path from the second node to the first node remain absent from the first window.

6. The method of claim 5, further comprising:
detecting a second selection of the second node of the second portion of the plurality of nodes, wherein the second node is visible in the first window; and
removing the second node from the first window.

7. The method of claim 1, further comprising:
detecting a selection of a selection element in the second window; and
removing all of the second portion of the plurality of nodes from the first window, responsive to the detecting the selection of the selection element in the second window.

8. The method of claim 1, further comprising:
detecting a selection of a selection element in the second window; and
making all of the second portion of the plurality of nodes visible in the first window,

responsive to the detecting the selection of the selection element in the second window.

9. The method of claim 1, wherein:
the second window includes a first popup window; and
the third window includes a second popup window.

10. A system, comprising:
a processor;
a display, coupled to the processor;
a user input device, coupled to the processor;
a storage subsystem, coupled to the processor; and
software stored on the storage subsystem, that when executed causes the system to perform:
generating a graphical representation of a service model comprising a plurality of nodes, each of the plurality of nodes representing one or more components modeled by the service model;
displaying in a first window on the display a first portion of the plurality of nodes, the first portion including a first node that is related to multiple nodes of the service model, the first window including a representation of the first node with an associated first target area and an associated second target area;
displaying, in response to determining that a cursor associated with the user input device is positioned with the first target area, a second window on the display including the first node and a second portion of the plurality of nodes coupled to the first node, the second portion of nodes being related to the first node and at least some of the second portion of the plurality of nodes being absent from the first window; and
displaying, in response to determining that the cursor is positioned with the second target area, a third window on the display including the first node and a third portion of the plurality of nodes coupled to the first node, the third portion being related to the first node and at least some of the third portion of the plurality of nodes being absent from the first window, wherein the third portion of nodes is disjoint from the second portion of nodes.

11. The system of claim 10, wherein the software when executed by the processor causes the system to perform:
removing the second window from the display in response to detecting that the cursor is positioned outside of the second window.

12. The system of claim 10, wherein the software when executed by the processor causes the system to perform:
removing the second window from the display in response to detecting a predefined input from the user input device.

13. The system of claim 10, wherein the software when executed by the processor causes the system to perform:
removing the third window from the display in response to detecting that the cursor is positioned outside of the third window.

14. The system of claim 10, wherein the software when executed by the processor causes the system to perform:
removing the third window from the display in response to detecting a predefined input from the user input device.

15. The system of claim 10, wherein the software when executed by the processor causes the system to perform:
displaying, on the display, information associated with a second node of the second portion of the plurality of nodes in response to detecting an interaction between the user input device and the second node displayed in the second window.

16. The system of claim 10, wherein:
the second window includes a first popup window; and
the third window includes a second popup window.

17. A non-transitory computer readable medium with instructions for a programmable control device stored thereon wherein the instructions cause the programmable control device to perform:
displaying, in a first window, a first portion of a plurality of nodes, each of the plurality of nodes representing a component modeled by a service model, the first portion including a first node that represents multiple subnodes of the service model and the first window displaying a representation of the first node with an associated first target area and an associated second target area;
displaying a second window in response to determining that a cursor is positioned substantially coincident with the first target area, the second window displaying the first node coupled to a second portion of the plurality of nodes, the second portion of the plurality of nodes being related to the first node and at least some of the second portion of the plurality of nodes displayed in the second window being absent from the first window and rooted to the first node; and
displaying a third window in response to determining that the cursor is positioned substantially coincident with the second target area, the third window displaying the first node coupled to that a third portion of the plurality of nodes, the third portion of the plurality of nodes being related to the first node and at least some of the third portion of the plurality of nodes displayed in the third window being absent from the first window and rooted to the first node, wherein the second portion and the third portion are disjoint.

18. The computer readable medium of claim 17, further comprising instructions that cause the programmable control device to perform:
detecting a selection of a second node of the second portion of the plurality of nodes; and
displaying the second node connected to the first node in the first window, wherein nodes in the second portion not in a path from the second node to the first node remaining absent from the first window.

19. The computer readable medium of claim 17, further comprising instructions that cause the programmable control device to perform:
detecting a selection of a second node of the second portion of the plurality of nodes, wherein the second node is visible in the first window; and
removing the second node from the first window.