USING ONLINE PERSONAL ONTOLOGIES TO SHARE EXPERIENCE ABOUT WEB RESOURCES

Grégory Bourguin and Arnaud Lewandowski University of Lille Nord de France, ULCO, LISIC

50, rue Ferdinand Buisson BP 719 62228 Calais Cedex France

ABSTRACT

Facing the myriad of web resources that are now available, the challenge we focus on is how to help users discover and select the most appropriate one for their particular needs. End-users feedback has been identified as a major source of inspiration in this process. In this paper, we draw an overview of existing solutions supporting it, and propose a prototype for completing these means while focusing on personal contexts of use of resources. Our ontology-based approach aims at letting end-users share the experience they have developed during their activities. This experience is crystallized in web resources aggregates that contextualize their task performance. We propose to describe and share these contexts through online personal ontologies that can be browsed thus providing entry points into the users’ universe.

KEYWORDS

End-user, resource, knowledge sharing, ontology, activity.

1. INTRODUCTION

The World Wide Web is constantly growing, offering an increasing set of resources to its users. These resources may range from software components, to stuff that can be bought online, or even information. Paradoxically, this plethora of available resources makes it difficult for users to discover and decide which is the one that will best fulfill their needs. As a result, many solutions emerge from the Web, trying to help end-users in their resources quest. They are part of applications stores, of large web sites like Amazon, or even concretized in smartphone applications like AppFlow that proposes some crowdsourcing app discovery. In all these solutions, users themselves are more and more involved while using Web 2.0 features to add information and meaning about the resources they use. These data are expected to help future users searching their own. This trend takes the form of end-users comments, rating, online tools for experience sharing (Singer, 2013) and social tagging (Saab, 2010)(Kim, 2008)(Knerr, 2006).

Despite of the indisputable success of these means, the large number of research papers denotes that there is still a lot of work that has to be done in order to better take benefits from information that can be provided and shared by end-users (Assimakopoulos, 2013)(Cabitza, 2014)(Deparis, 2013)(Gayo, 2009). Users usually still have to start using a resource to test it and determine if it actually fits well in their task and context of use. This process is time consuming and may result in money lost. Moreover, this shift has a lot of chances to happen since users often do not have an exact idea of what they are looking for while seeking inspiration.

In the first part of this paper, we underline the benefits and the lacks we found in existing web solutions that currently try to help users identify resources that are useful in their own context. In the second part, we propose a new approach that does not aim at replacing these widely used solutions, but that has been designed to complete them. This activity-based approach aims at letting users share the experience that has crystallized in the web resources aggregates they created during their activities. The third part describes a scenario set up to verify the feasibility of our approach: a prototype has been developed in order to let a user model her experience into personal ontologies. The modeled elements can then be used as entry points into the user’s universe. We also describe how this representation can be integrated into an existing media, so that others can browse, discover and understand linked web resources in concrete contexts of use.

2. RESOURCES AND END-USERS IN WEB 2.0

Discovering and selecting a resource for realizing a particular task implies that the potential user can clearly understand what can be done with it in its particular context. Many web sites offer web resources that are organized into fixed categories. This type of categorization matters in only offering the arbitrary creators’ point of view (Gayo, 2009). This does not necessarily help the user in discovering a resource, and understanding what it can serve for him, since the resource could have been categorized differently from another point of view. We will indeed see later in this paper that research around social tagging and folksonomies (Mathes, 2004) tries to overcome this problem (Saab, 2010)(Gayo, 2009)(Knerr, 2006).

Repositories like Eclipse Marketplace, Curse or mobile apps stores categorize their resources around the generic task that each component has been designed to support. There is usually a shift between this generic task and the particular user’s one. As a result, the users have to imagine and decide if the generic task in which the resource has been categorized will match in their own particular one. This decision is hard to take since a generic category usually offers many solutions corresponding to the same generic task. A new question then arises: which one of these a priori equivalent but different resources will better fulfill the needs. A resource is rarely used alone and one of the most important criteria that can help in selecting it is how this resource will complete and integrate with other resources that participate to the user’s task. Unfortunately, generic categorization does not help much in answering this question.

2.1 Involving end-users

Tagging systems are nowadays commonly used in filling in the gap between fixed resources categorization, and their end-users points of view. Tagging has also been successfully used to overcome many problems related to the classic hierarchical organization of resources (Oleksik, 2009)(Hsieh, 2008). This approach has led to great success while letting self-organized communities create folksonomies (Knerr, 2006). Kim (2008) underlines that tags actually reflect personal views of the world by individual users. Saab (2010) indicates that tags “form the entry points into our complex intrapersonal schemas and rich ontological understanding of experience”. However, Kim also underlines the lack of semantic representation in tagging systems. Moreover, Saab explains how classical folksonomies can only be considered as reflections of cultural schemas only for dominant cultural groups. Actually, a lot of work still has to be realized in tagging systems while less considering taggers in the masses and keeping track of the links between a tag, its creator and the context in which the tag was created. Most repositories nowadays include a rating system in which end-users can rank the available web resources. This type of information allows evaluating if a resource has been acclaimed by a large number of users. This certainly means that the resource supports a generic task that generally fits well in the particular tasks of most users. However, this information can hide the fact that, even if they do not satisfy the masses, other resources may better match with the tasks of some users. Accompanying comments are interesting by distinguishing particular users from the masses. These targeted explanations may provide information about the commenter and the context in which the resource has been used. It can help the readers to evaluate if the commenter ranked the resource in a context that matches their own. Unfortunately, the free form of comments makes such information (if available) mostly implicit, unstructured and hard to extract. Some repositories explicitly show which user has been satisfied with a resource while also providing some structured information about its context. The “Favorited by” section of each Eclipse Marketplace solution shows the name of each user and provides a link to the list of his other favorite Marketplace solutions. This list offers a global view of the task types the commenter is involved in. This lets better imagine its context and gives more meaning to its rating or comments. It provides information about which resources can complete the others in a global task. However, even if interesting, this information is both too general and too specific. It is too general because the full list of a user’s favorite resources do not really let understand the particular tasks this user is involved in: only subsets of these resources are certainly used in specific tasks. There is no information about the concrete user’s (sub-)tasks these resources are used in. And it is too specific in the sense that the favorite resources compilation do not reference other resources that are also involved in the user’s task, but that are coming from outside of the repository.

2.2 Going deeper into end-users experience

An approach to overcome these issues is to focus on particular users while distinguishing their own experience instead of considering them in the mass. This approach is coherent with the results of studies presented in (Draxler, 2011). The authors highlight the fact that adoption of resources in software ecosystems more easily happens between users who know each other and share their working context. In accordance with this, different tools have recently emerged in the Eclipse ecosystem (Draxler, 2009)(Bourguin, 2012). All these solutions are restricted to the Eclipse ecosystem. Specialized social networks focus on mutual assistance between their users: Stack Overflow and GitHub allow software developers to share their experience about different topics. Such information reveals to be helpful in many ways (Dabbish, 2012), and facilitates the development of Communities of Practices (Assimakoupoulos, 2013). However these systems do not explicitly help in discovering and understanding the whole set of resources involved by each user for a particular task. Masterbranch and Coderwall aim at offering a more global point of view on developers’ contexts. Singer (2013) shows that these profile aggregators facilitate mutual learning. Once again, these systems do not explicitly offers the sharing of experience about web resources we are looking for. However, the study highlights that users like sharing their experience while desiring recognition by peers. Moreover, they underline that investigating other’s universe (creations, languages, etc.) helps users to assess others, and then to be inspired from them. This point is very important for us: discovering one’s context (tasks, resources used to realize them) helps to understand him, and favors inspiration by discovering new resources, and new things to do with.

Some popular web tools like weblogs, forums, wikis or YouTube are nowadays particularly involved by end-users to let others enter and discover their universe. The productions act as tutorials and correspond to one of the more precise source of information for discovering resources in a context of use, and for being inspired. For example, many scrapbooking blogs offer posts showing the result of an activity (a scrapbooking layout), and citing resources that have been involved in this realization (papers, stamps or photo editing application). Some scrapbooking commercial sites involve their own customers in design teams whose aim is to show what can be realized with their products: selected customers receive free resources packs and have to propose a realization that uses them. The user then creates a post that shows the result, and references the involved resources. Some computer games editors maintain official blogs that highlights selected gamers who present some of their characters builds, i.e. particular assemblages of game’s resources. Each resource of these games is usually fully described in web databases or wikis. Each build aggregates resources and is dedicated to a particular user’s way of playing. YouTube contains many users’ video tutorials in which a gamer shows a character in action, and gives comments on how to best use the selected resources.

All these means are today widely used to share experience around resource aggregates. Unfortunately, all these descriptions are mainly made informally and it is almost impossible to browse deeply the links that may exist between a user’s resources and activities. Users are usually involved in multiple similar activities. Discovering that a user uses a specific resource in a particular activity could lead to discover that this user is also implied in other activities of the same type. A similar but different activity certainly involves a different resources aggregate: others may discover and adopt better and unexpected resources. Reciprocally, users often involve a same resource in different activities. Discovering that a resource, or a type of resource, is involved in different activities may help in understanding what can be done with it, and may inspire by discovering it in unexpected aggregates built for unexpected purposes. As an example, a player that tries to create its own build is mainly looking for inspiration by browsing different video tutorials and posts. It is today almost impossible to know that a resource that is referenced in a player’s build has also been used in a variant of this build, or in some totally different ones. All these builds are often indeed described in other videos of the same channel. They may help to better understand what can be done with this resource, to better discover this user’s context, and eventually be inspired from it. The lack of links representation thus slows down discovery, understanding, assessment and inspiration. YouTube and blogging systems nowadays provide tagging mechanisms that partially palliate this issue: a post can be tagged and readers can select a set of tags to discover similar posts. This solution does not totally help since these tagging mechanisms are designed to describe each post in a whole. There is no mean to create a tag that semantically only applies to sub-elements like a particular resource that is referenced in the tutorial. More generally, the totally free form of these tags does not help in representing the semantic links that exist and can be inferred between resources and activities.

3. INTRODUCING ONLINE PERSONAL ONTOLOGIES

The previous analysis shows that the web offers many means to discover, understand and help selecting appropriate web resources for a particular purpose while taking benefits from end-users’ experience. If interesting, these means are only part of the solution. Many systems limit the experience that can be shared to only a part of the user’s activity by restricting the type of resources that are represented. Systems enabling more free form of descriptions are lacking semantic that can help in presenting the links between their constituting elements. As a result, end-users’ experience can nowadays mostly be shared, but it is disseminated between many different systems, or even between different parts of the same system. Our assumption is that the global picture can be enhanced by a new solution.

Our proposition is called EVOXEL. This solution aims at facilitating the discovery of one’s experience by allowing others to browse his universe. The idea is to let end-users freely model the concrete contexts in which they involve different resources aggregates. The meta-model has to be flexible to let users describe their own points of view, but has to introduce the minimum of semantic that will facilitate to browse them deeply. The produced models will then correspond to personal ontologies that describe a user’s resources in their context of use, and that establish the links between them. Our goal is not to replace existing solutions, but to complement them. We want to let users share their experience by populating web existing solutions with entry points into their personal ontologies. These ontologies can thus be considered as user maps that allow others to discover and understand web resources in concrete contexts of use.

3.1 Context of use and activity concept

Research has successfully used the activity (or task realization) concept to represent users’ contexts notions. Oleksik (2009) differentiates between activity management and information management. User’s activities representations have served in projects considering activity management and trying to overcome the drawbacks of the traditional desktop metaphor (Kersten, 2012). This research demonstrates that the activity concept better matches end-user’s representation of their work, better fits with real world organizations, and facilitates the management of resources while often switching from one task to another. Projects focusing on information management criticize the omnipresent hierarchical structure used to store (and retrieve) personal resources (Hsieh, 2008), and propose activity-based tagging systems to overcome the identified issues (Voida, 2009). Oleksik (2009) underlines benefits from activity tagging of resources and reports “the [users’] perceived value of the resources assembled through a task or activity”. From our point of view, strongly influenced by the Activity Theory (AT) (Kuutti, 1993), a resource aggregate developed by a user during an activity crystallizes its experience concerning this activity. Sharing a resource aggregate is sharing experience about a concrete particular context of use. All these elements advocate for using the activity concept to let end-users describe their personal ontologies. These ontologies are meant to be easily manipulated, shared and browsed on the web. We thus have used the Ontology Web Language (OWL) for creating the meta-model that resides in the core of EVOXEL. Our goal is to let end-users describe basic links between their resources and activities. Such meta-model should contain very few entities, thus facilitating its learning. We thus have built an activity meta-model inspired by (Kuutti, 1993) using AT to describe organizations of activities. This meta-model is presented in Figure 1. One can notice that this model only references one actor by activity. This is due to our focus in this paper: sharing personal ontologies, i.e. models (or abstractions) focusing on particular point of view on his resources and activities.

Figure 1. EVOXEL ontological meta-model for representing a user’s personal ontology

3.2 The EVOXEL prototype

In order to explain how EVOXEL works, we will now introduce a scenario that has been set up. We want to underline the fact that this work is not an evaluation of EVOXEL. The case we present here aims at showing how a non-IT person can use EVOXEL and testing the feasibility our approach.

3.2.1 An example of Scrapbooking activities We asked a blogger to test EVOXEL. She has been involved in scrapbooking activities for many years and she is involved into scrapbooking design teams, and regularly products web content. The goal of a design team is to show the realizations of its members, in order to inspire followers. A post generally contains a text explaining the realization, a couple of photos, and a list of used materials. These materials – or resources – are mainly papers, embellishments, pens, markers, adhesives or jackets from different brands, but can also be a software (e.g. smartphone application) that has been used for applying picture effects (sepia, etc.) on some photos of the scrapbook page, or even real tools such as stamps, scissors, punches, etc.

Blogger system is used to publish the blog. This weblog publishing tool includes a WYSIWYG interface to compose and edit posts. The generated HTML code can also be modified to allow finer adjustments. However, our user being a non-IT, she uses this functionality very rarely. Blogger allows writers to tags their posts, up to 20 labels per post. Our user is familiar with this functionality, and generally tags each post with 2 to 4 labels (e.g. “scrapbooking, holidays, travel”). These labels help categorizing posts in a global way.

3.2.2 Activity modeling First of all, a personal ontology must be constructed. In the current version of the prototype, this is done thanks to a desktop tool. This modeler has been developed in Java, and the core of the tool uses the OWL API in order to generate and manipulate ontologies created from the EVOXEL ontological meta-model, so that the user has very few concepts to deal with. The user first creates a new personal ontology and gives it a name. In our example, an ontology named “Papier et moi” has been created – this is also the title of the weblog. This ontology will describe the activities detailed on the weblog.

Figure 2. Screenshot of the EVOXEL modeler: (a) main editing window and (b) alternative tags tab

Using the graphical user interface, the blogger can create activities and resources, and link them together.

She can also tag these elements (cf. Figure 2). Nothing very different from what she does on the weblog. An activity in the personal ontology corresponds to a post describing a layout in the weblog. A resource in the

personal ontology may correspond to a material mentioned in the weblog. The modeler can show the whole graph containing all the activities of the ontology, and can also zoom in a particular activity. Figure 2 (a) shows the zooming on the “Happy for you” activity, which corresponds to a post describing a specific layout. On the left, a repository tab shows all the elements – actor, activities and resources – belonging to the ontology, and can filter them according to their type. Elements of this repository can be drag-and-dropped on the graph. Indeed, some resources may be involved in several activities. An activity can also be sub-activity of several other ones.

Another tab is available, listing all the tags created by the user in order to label the many elements of his personal ontology. In the underlying OWL model, these tags correspond to specialization of the basic types (#Activity, #Resource, and #Actor) mentioned above. Users can create their own tag hierarchy by telling that a tag specializes another one. In Figure 2 (b), the blogger has created a sub-category “Stuff”, and other tags that specialize this category: “Alphabet”, “Stickers”, etc. Again, these tags can be drag-and-dropped on a graph element of the personal ontology, in order to label this particular element with this tag. The JFact OWL reasoner is coupled with the GUI to prevent from ontology inconsistency.

The modeler inspector (Figure 3) can be used to finely complete elements description. It also can be used to browse the edited ontology thanks to the underlying JFact reasoner. For example, double-clicking on an element in the repository shows a synthetic view with all the current information that can be retrieved and inferred about it (inherited types, links with other elements, etc.). A specific field helps in adding URLs towards web resources corresponding to this element. For example, it can be a link towards a post of the weblog, an article, a product page in a web store, etc. This synthetic view facilitates browsing the ontology, since every element is a hyperlink that points to its synthetic view.

The result of this editing process consists in a generated OWL file describing the personal ontology. This file can be uploaded (“publish” button) on the EVOXEL server, which stores and shares personal ontologies.

Figure 3. Screenshot of the EVOXEL modeler inspector

3.2.3 Sharing personal ontologies Each element of the personal ontology (activity, resource, actor or tag) has its own URL that offers a specific entry point to this ontology hosted on the EVOXEL server. These URL can be copied into the clipboard, or dragged from the modeler to be pasted on the web: on a weblog, in a comment, a YouTube channel, etc.

Figure 4. Entering a personal ontology through a “simple” link inserted in a weblog

In Figure 4, while writing her post, our blogger has selected the text where she describes her “cherish velum” resource and just added the URL by drag-and-drop from the modeler. The resulting link leads to a synthetic view generated by the EVOXEL server. This view shows the place of this element in our blogger’s personal ontology. This view contains URL towards external websites (e.g. where to buy this stuff) and links towards all the elements this stuff is related to: similar entities, others activities using it, etc. One can thus discover that this vellum named “Gold Punchinella” is also used in another activity named “Fabulous”. Clicking the name of this activity opens its synthetic EVOXEL view, indicating its resources, their types, the corresponding post in the weblog, and so on... The URL inserted into the weblog really acts as an entry point into the user’s experience, inferred from the resource, and that can be browsed from one element to another.

4. CONCLUSION

Facing the myriad of available web resources, we have focused on how to help users discovering and selecting the most appropriate one for their particular needs. In research and industry, end-users feedback has been identified as a major source of inspiration in this process and many solutions are commonly set up. We have shown how these means are all interesting, but also how they are partitioned and lack semantic that can help to link their constituting elements. As a result, end-users’ experience is disseminated and can hardly be browsed. We then have proposed an approach and a prototype named EVOXEL. This solution has been

designed to complement these widely used existing means. EVOXEL introduces an OWL activity-based meta-model, a modeler and a web repository that let users share personal ontologies that describe their experience crystallized in the resources aggregates they built for supporting particular needs. We have tested the feasibility of our approach and presented a scenario showing how a non-IT person has used EVOXEL in the context of a scrapbooking weblog. Our user successfully described, tagged and linked resources and activities. She felt this process cost was a little effort: even if they were more synthetic, framed and exhaustive, her descriptions were similar to those usually contained in her posts. Moreover, she also felt that her personal ontology could offer a direct gain for herself while serving as a reminder of the elements that should be dragged in the weblog. We have shown how, using a JFact ontological reasoner, each element of the online personal ontology provides an URL that can easily be inserted in existing web solutions. Each URL serves as an entry point into a user’s point of view and experience that can be browsed for discovering, understanding and being inspired by the use of web resources in concrete particular contexts.

We are currently planning user studies involving consequent sets of users. As one can expect, our first sample will be dedicated to a full scrapbooking design team. Our first tests and our users’ anticipations about these new discovery means, and the resulting enhancement of their posts visibility, is however encouraging.

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