Content Management
4.1 Content-based Services to Support CM
4.1.3 Dynamic Identification of Applicable Services
Currently, web-based interfaces present a variety of graphical objects to support the inter-action of the end user with the application. Graphical objects such as menus, drop-down lists, buttons, check boxes, etc., commonly provide a static set of items. Such items invoke services to execute the corresponding code that implements the application’s functionali-ty. Thus, it is through those items that the interface provides access to the application’s functionality. In the context of semantics-driven applications, the items presented by the application do not only reflect the application’s purpose, but also the domain semantics of the media content being managed by the application. For example, currently, text editors allow users to insert different types of objects to help illustrate the text, e.g., pictures, clipart, shapes, graphics, etc. To allow this, a menu is commonly offered where each menu-item corresponds to the type of object to insert. If a text editor uses content des-criptions, its functionality can be adapted to offer content-related services. In this way if
Figure 4.6: In-text advertisement.
the text content is related to the athletics domain and the user decides to insert an object, e.g., an image, then domain related objects are suggested, e.g., an image of an athletics event. If the domain of interest changes, then correspondingly the application services adapt to the domain. Thus, in the context of semantics-driven applications, services can be parameterized with information about the content semantics of media.
The objective of this section is to describe how the content descriptions obtained from SLI, DLI and fusion processes can be used to dynamically determine the association of content-based services (from a predefined set) with a graphical element of the interface, e.g., a context menu. To explain the process of association, we will use examples of the services implemented in the BSB application. The BSB offers browsing functionality over athletics news. To support this functionality asearch-by-association approach is used. As described in [SWS+00], in search-by-association, at the beginning users have no specific aim other than finding interesting media. Search-by-association often implies iterative refinement of the search by using the similarity of the content with which the search started. This browsing approach is described later on in detail in Chapter 5.
In the BSB, text from web pages as well as images contain active content which is used by end users to interact with the application in order to access context menus. Each item of such context menus (see Figure 4.7) corresponds to a service (from a predefined set of services), which executes the corresponding code that implements the functionality of the application. The available services are dynamically assigned to a context menu according to the annotations related to the active content.
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Figure 4.7: Context menus for active content in the BOEMIE Semantic Browser.
As Figure 4.8 shows (see page 115), the active content are such segments of media content that have been annotated. In this example, the highlighted segment in the image corresponds to an instance ofHorizontalBar. Thus, segments are directly associated with SLI results, given that segments belong to explicit observations within media content.
From SLI results a system can have access to DLI and fusion results by querying the corresponding Abox.
For example, Figure 4.9 shows a segment from text with related interpretation results.
As shown, the highlighted segment corresponds to an instance of typePersonName. While this is obtained from SLI results, by observing the segment’s surrounding text, it should be clear that DLI results should explain that the name is related to an instance ofPerson through a role hasName. Moreover, the instance of type Person is also of type Athlete, more specifically, a JavelinThrower. With the use of reasoning services, on top of in-terpretation results, top-down information flow can be obtained from DLI results that make SLI results more specific. In this example, the highlighted segment in Figure 4.9 is associated, implicitly, with an instance ofJavelinThrowerName provided an axiom in the TBox such as J avelinT hrower v ∀hasN ame.J avelinT hrowerN ame. In this way DLI results contribute in making SLI results more precise.
Figure 4.8: SLI and DLI results of an image.
The dynamic composition of context menu-items is determined by the content seman-tics related to the active content through annotations. The annotations are used for the identification of so-called applicable services. As Figure 4.7 shows, a context menu for the horizontal bar is accessed containing the following items:
1. Buy Athletics Equipment at Sportswarehouse 2. Definition of person
3. More images of Kajsa Bergqvist being referenced as athlete 4. More images of jumping trials
5. More jumper images
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7. More high jumper images
Each item corresponds to an applicable service. The applicability of a service is de-termined by the parameters that the service requires as input. Thus, input parameters are typed with terms from the domain ontology, e.g., the AEO ontology. Given the SLI results related to the segment in Figure 4.8, more specifically id5 : HorizontalBar, di-fferent applicable services are discovered and shown as items in the context menu. The first item calls a service that requires an argument of typeAthleticsEquipment. Thus, the first item is activated by reasoning on SLI results since according to the AEO ontology (see Appendix A in page 145)HorizontalBar is anAthleticsEquipment. The second item relates to a service that requires as input an argument of typePerson, thus this service is applicable due to DLI results which involve an instance of type Person (see Figure 4.8).
Figure 4.9: SLI and DLI results of text.
The third item relates to a service that requires an instance of type Athlete in relation to an instance of type PersonName with a specific value. In this case the name Kajsa Bergqvist comes from the fusion of individual new3 with another instance coming from text (fusion results are omitted in Figure 4.8). The fourth item relates to a service whose argument is of type Jumping, thus it is applicable by reasoning on DLI results, since individual new4 is of type HighJump and according to the AEO ontology HighJump is a specific type of a Jumping trial. The following three items require arguments of type Jumper,HighJump andHighJumper which are applicable by reasoning on the individuals new3 and new4 of Figure 4.8. In this way, the applicability of a service is determined by the annotations related to the active content previously accessed. A more specific description of how service applicability is implemented will be given in Chapter 5.
The general principle behind this scenario is that provided a set of services that use ontology terms to type their input parameters, as well as content descriptions associated to specific segments of content, reasoning can be used to find the association between services and media, and correspondingly configure the items of graphical elements in an interface that adapts to media content.
In the BSB application, the content-based services provided are primarily to support web navigation,target search andactivation of tools. The first is useful for placing seman-tically related content that can be reached through a hypertext link. This functionality is suitable for advertisement purposes. The second is useful for browsing purposes to be more specific as a target search, thus the system suggests semantically related content, e.g., image, text or video, that can be reached through a query over a triple store repo-sitory. For example, the target search can be another image of the same object which the user has activated. Finally, the third service shows that semantics can be used as arguments to access the application’s internal methods, for example, for the activation of the map tool. In the BSB, context menus are accessed through a click on the segments that indicate active objects of an image (see Figure 4.7) or active words in the text of a web page. Note that the relevance of this scenario relies on the dynamic composition of items and not on the specific graphical objects used. Thus, the same principle can be used to support other types of graphical objects, for example, to influence the content of side bars typically used for advertisement, items of drop-down lists, etc.
To explain the implementation of the scenarios described in this section in more detail, the following Section 5 describes the required architecture and the implementation of the BSB.
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