Developing a Semantic User Preferences and Device Modeling Framework that supports Adaptability of Web Applications for People with Special Needs
- Philip Ackermann, Fraunhofer Institute for Applied Information Technology FIT, email@example.com
- Carlos A Velasco, Fraunhofer Institute for Applied Information Technology FIT, firstname.lastname@example.org
- Evangelos Vlachogiannis, Fraunhofer Institute for Applied Information Technology FIT, email@example.com
Introduction and background
The introduction of user and device models to customize applications has been the subject of research for decades. This position paper presents a modeling framework that supports dynamic adaptations of the user interface of web applications. This work builds upon previous efforts of the authors (Velasco et. al. 2004) leveraged with the use of the semantic framework Composite Capability/Preference Profiles (CC/PP, (CC/PP, 2007), which allows the matching of device capabilities and user preferences. The combination of these models with those of the corresponding web applications, enables an adaptive transformation process that facilitates access to users with special needs, derived of their functional restrictions or because of context-related handicapping situations. Our approach differs from traditional user models based upon cognitive or physiological characteristics of the users.
Approach and framework components
Our models are based upon the Composite Capability/Preference Profiles (CC/PP) 2.0 (CC/PP, 2007) RDF framework. CC/PP enables a description of device capabilities and user preferences that can be used to guide the adaptation of content. CC/PP allows to construct user and device profiles as a two level hierarchy: a profile with a number of components, which have a number of attributes. The attributes of a component may be included directly in a profile document, or may be specified by reference. This simple framework allows an efficient processing of profiles without the parsing overhead of more complex semantic models based on OWL, for instance. The framework has three major components, which are described in the following:
- web technology model
- device model
- user preferences model
One of the novelties of our approach is the definition of a decoupled web technology model, which could be used by any other component of our architecture. This approach offers several advantages: (i) it allows the expression of device capabilities for either hardware or software components; (ii) it allows the expression of user preferences; and (iii) it simplifies the expression of matching rules for adaptation with different granularities, ranging from top components like, i.e., images or movies to HTML elements and attributes, or CSS properties, for instance. The model is characterized by a hierarchy of classes, in which subclasses like MarkupTechnology, XMLTechnology or StyleTechnology include containers for their constituting parts. The model is available at: http://i2web.eu/ns/2012/technology#.
Our approach for the device model is similar to that of UAProf (User Agent Profile, 2006). Due to its limitations, we decided not to extend UAProf but to design our own vocabulary, denoting a semantic equivalence or difference where appropriate (the model is available at: http://i2web.eu/ns/2012/devicemodel#). The main components are:
- HardwarePlatform: the HardwarePlatform component is used as a generic platform description. It is different from HardwarePlatform in UAProf, which contains properties of the device's hardware, such as display size, supported character sets, etc.
- Hardware: this component identifies individual hardware elements like displays, graphic cards, sound cards, keyboards, mice, etc. It can also be used to identify assistive technology hardware like Braille-lines, etc.
- SoftwarePlatform: the SoftwarePlatform component is used as the operating system description of the device. Again, it is different from the UAProf SoftwarePlatform component, which contains properties of the device's application environment, operating system, and installed software.
- Software: this component identifies individual software components of the device. We distinguish two subclasses: ApplicationSoftware (software that performs some kind of activity for the user) and InteractionSoftware (software that supports the interaction of the user with the device like a screen-reader, an onscreen keyboard, etc.). A key subclass from the former is the UserAgent class, used to define software that retrieves and renders web content for users and is similar to the UAProf BrowserUA component.
After evaluating different approaches, we have focused on modeling the user preferences and not her physiological characteristics. On that way, we can focus on transforming different UI components. Our work is based upon the CAMELEON Unified Reference Framework (Calvary et. al. 2002) and (Calvary et. al., 2003), which “… is a framework that serves as a reference for classifying user interfaces supporting multiple targets, or multiple contexts of use in the field of context-aware computing.” Furthermore, following the work of the SERENOA project, we have newly introduced a semantic container that holds categories of pre-defined transformations, which can be mapped to algorithms similar to those of the library of algorithms for advanced adaptation logic defined by SERENOA (SERENOA Project, 2012). Due to the abstraction level introduced by the Web Technology model, we can avoid redundancies in their classification due to different content-types. The latest version of this model can be found online at: http://i2web.eu/ns/2012/usermodel#.
transport of the models is solved via two additional extended HTTP headers:
x-i2web-uprof for user preferences profiles and
x-i2web-dprof for device profiles. These headers are general
header fields which MUST contain the following:
- an absolute URI referencing the profile (as defined by RFC2396), or
- an RDF profile instance serialized as RDF/JSON.
The whole modelling infrastructure is being made available through a Model Management System (MMS). The MMS is an assistive system that supports the user in configuring her preferences and in detecting the configuration of her system (operating system, browser and assistive technologies), while it enables model-aware web applications to react dynamically to these specific devices and user preferences. The MMS system completes a set of open interfaces that allow the integration of the infrastructure into third-party products and systems. With the help of the MMS, users communicate their preferences and the characteristics of their systems to applications in a transparent form to them, and enable the communication of clients with the model repositories. The system also provides a multiplatform configuration user interface to support end users to define their preferences.
User and expert evaluation
The i2web project uses a highly user-centered approach, working closely with the various user groups, and has conducted both expert and user evaluations and several field studies throughout the project. We have validated the modelling framework through these user and expert tests, which implemented our framework in three different web applications. The results of these evaluations are reported in (Power et. al. 2013). Additionally, the user interface of the MMS has been subject to 3 evaluation rounds by accessibility experts and end-users, which has led to 3 designs that improve the accessibility and usability of the system.
Conclusions and future work
The whole modeling framework has been used to adapt industrial applications in three domains (e-goverment, online banking and video on-demand services) under the scope of the Inclusive Future-Internet Web Services (i2web) project. These implementations have demonstrated the feasibility of our approach through extensive user testing. Future work is targeted to the extension of the models to include further standard preferences of users and state-of-the-art devices, assistive technologies and user agents.
Parts of this work have been undertaken under the framework of the Inclusive Future-Internet Web Services (i2web) project, co-financed by the 7th Framework Programme of the European Commission under its ICT Programme (Grant Agreement number 257623).
- G. Calvary, J. Coutaz, L. Bouillon, M. Florins, Q. Limbourg, L. Marucci, F. Paterno, C. Santoro, N. Souchon, D. Thevenin, and J. Vanderdonckt. The CAMELEON Reference Framework. Technical report, CAMELEON Project, IST-2000-30104, 2002.
- G. Calvary, J. Coutaz, D. Thevenin, Q. Limbourg, L. Bouillon, and J. Vanderdonckt. A Unifying Reference Framework for multi-target user interfaces. Interacting with Computers, 15(3):289-308, June 2003. DOI: http://dx.doi.org/10.1016/S0953-5438(03)00010-9
- Composite Capability/Preference Profiles (CC/PP): Structure and Vocabularies 2.0, W3C Working Draft 30 April 2007. Cédric Kiss (editor). Available at: http://www.w3.org/TR/2007/WD-CCPP-struct-vocab2-20070430/
- Power, C, Petrie, H, Swallow, D, Murphy, E, Gallagher, B, Velasco C.A. (2013). Navigating, Discovering and Exploring the Web: Strategies used by People with Print Disabilities on Interactive Websites. Proceedings of INTERACT 2013, 14th IFIP TC13 Conference on Human-Computer Interaction. 2-6 Sep 2013, Cape Town, South Africa. To appear.
- SERENOA Project, Deliverable 4.2.2, Algorithms for Advanced Adaptation Logic (2012). V. G. Motti, N. Mezhoudi, J. Vanderdonckt (editors). Available at: http://www.serenoa-fp7.eu/wp-content/uploads/2012/10/SERENOA_D4.2.1.pdf
- User Agent Profile, Approved Version 2.0 – 06 Feb 2006. Open Mobile Alliance, OMA-TS-UAProf-V2_0-20060206-A. Available at: http://bit.ly/11SdIqR
- C. A. Velasco, Y. Mohamad, A. S. Gilman, N. Viorres, E. Vlachogiannis, A. Arnellos, and J. S. Darzentas. Universal access to information services | the need for user information and its relationship to device profiles. Universal Access in the Information Society, 3(1):88-95, Mar. 2004. DOI: http://dx.doi.org/10.1007/s10209-003-0075-5