Theoretical contributions

The theoretical achievements of this research are highlighted in the investigation done into AUIs and SOA. The achievements include:

 Research into SOA and AUIs;

 The development of a method for the analysis and design of an AUI using SOA;

 The application of this method and its outcome the AUI services model; and

 The evaluation strategy used to evaluate the model and the prototype developed as a proof of concept.

7.2.1.1 Literature review

Service-oriented architectures (SOA)

Research Questions addressed: R1 - What is SOA and what are its components?

This study undertook an in depth investigation of SOA and its components in Chapter 2. Its relation to enterprise architectures (EA) and distributed architectures highlighted the similarities as well as the differences between SOA and architectures similar to it. SOA is an architectural

style and design paradigm that advocates the loosely coupled and agnostic design and construction of distributed systems. The construction of a system in this way enables the system to be agile and thus more adaptable to changing business requirements. The components of a system are consequently designed as services. SOA applications and system consist of three main components, namely, the service consumer, the service provider and the registry.

A service is an autonomous unit of functionality. Essentially, it provides a discrete function in a stateless and agnostic environment. Services or applications, referred to as service consumers, can re-use a service‘s functionality without having to implement it themselves. This is achieved by invoking the service, which subsequently performs its function and, if that is part of its function, returns a value.

Various standards exist to facilitate the searching, linking and invocation of services (Bellwood et al. 2004; W3C 2006; W3C 2007; W3C 2009d). Universal Discovery Description and Integration (UDDI) is a repository protocol which allows service consumers to search a repository of services based on the descriptions of services. Service consumers are then capable of bind to any service, using the services‘ interface defined by the WSDL.

Web Services Description Language (WSDL) defines the operations of a service and how external applications or other services can bind to the service in order to invoke its functionality.

Simple Object Access Protocol, now simply known as SOAP, is a transportation protocol used to transport messages between services providers and service consumers.

Adaptive User Interfaces (AUI)

Research question addressed: R2 - What are AUIs and what are the components of an AUI?

Chapter 3 discussed the topic of AUIs. Research into AUIs has increased in recent years due to the increasing complexity of applications and their UIs. The aim of AUIs is to increase the flow of information between humans and computers by adapting the UI. AUIs provide a variety of functions, such as automatic completion of mundane tasks, giving advice about system use or controlling a dialogue. These functions assist the users of AUIs in achieving their goals with the system. Most notably, AUIs can adapt the UI to suit the needs, preferences or traits of its users.

This is achieved by modelling users and monitoring the characteristics which differentiate users.

An AUI can be separated into three distinct components, namely: the inferential, afferential and efferential components of adaptivity. The afferential component captures user-interaction data and stores the data in the knowledge base. The knowledge base is a collection of models about the AUIs environment including the user, the task, the system and the domain. The AUI uses information in the knowledge base to make inferences about its environment and adapt itself if necessary. This inferring functionality is provided by the inferential component.

The inferential component uses various methods to analyse the AUIs environment by using the data stored in the knowledge base. It subsequently makes inferences about the environment. The afferential component decides how to adapt the AUI based on the inferences made by the inferential component.

7.2.1.2 Service-oriented analysis and design method

Research question addressed: R3 - How can an AUI be designed using an SOA?

Existing service-oriented (SO) analysis and design methods are either proprietary or have not been proven as being effective through extensive use in industry. As such a hybrid method was devised in the analysis and design of the model for this study. This method combined two existing methods, namely, SOMA (Arsanjani 2004) by IBM, and Erl‘s (2008) SO analysis and development method (SOADM). SOMA is a proprietary method. IBM, however, provides sufficient information (Arsanjani 2004; Arsanjani et al. 2008) about the higher level components of this process to understand the process and possibly to apply it.

SOMA is an industry proven but proprietary method, and as such information on specific aspects of the SOMA process is not publicly available (Ramollari et al. 2007). SOADM, although unproven in industry, provides details on specific aspects of SO analysis and design. The specific details provided SOADM, which relate to components found in SOMA, provide vital information that is not made public in the SOMA method. As such, SOADM specifics are used to complement the SOMA method and a hybrid SO analysis and design method is the result.

The hybrid approach consisted of the three components of the SOMA approach, namely: SO Analysis (Section 4.3), Design (Section 4.4) and Realisation (Section 4.5). SO Analysis consisted of the definition of requirements (Section 4.3.1) and identification of automated

systems (Section 4.3.2). SO Design consisted of the composition of SOA by selecting the appropriate service layers (Section 4.4.1), designing services using service specifications (Section 4.4.2.1) and designing SO processes (Section 4.4.3). The final step of the process was the decision on how to realise the services (Section 4.5).

7.2.1.3 AUI services model

Research question addressed: R3 - How can an AUI be designed using an SOA?

The AUI services model developed in this research provides a means for AUI services to be implemented in a network and accessed as a discrete function. The model, by virtue of being implemented as services, is a collection of loosely coupled AUI components that interact together to provide adaptation functions.

Research into SOAs has shown the increased adoption of this architectural style to integrate disparate platforms. A major hurdle identified is how to establish the right UI with which end-users can access information in an SOA. Various approaches exist as solutions to this problem such as web-based Portlets or desktop-based smart clients (Tibco 2006). By their very nature, integrated systems are high information environments. A second and sometimes less obvious issue with UIs in high information environments is that end-users of the UIs differ in many ways.

End-users differ in preference, ability and needs; and currently UIs for integrated systems or complex desktop systems for that matter, do not adequately address this difference. AUIs have been proposed as a solution for this problem.

This research consequently developed a model for AUIs based on existing SOA and web services UI methods to provide an AUI services model (Figure 7.1). This model was developed by applying the SO analysis and design method described in Sections 4.3 and 4.4 to an existing AUI scenario.

The model consists of services developed around traditional AUI components: the afferential component, the inferential component and the efferential component of adaptivity. The afferential component of adaptivity (Section 3.2.5.1) consists of a Watcher Service which captures data and stores them in the knowledge base.

The AUI services model uses a knowledge base consisting of a user and task model. The user model stores characteristics that distinguish users from each other, for example, performance-related information. The task model defines the task(s) that the end-users perform and which the AUI monitors.

The inferential component of adaptivity (Section 3.2.5.2) consists of an Analysis Engine Service which performs user modelling on the user-interaction data captured by the Watcher Service.

Finally, the efferential component of adaptivity (Section 3.2.5.3) consists of a Transformation Service which uses output from the user modelling component, the Analysis Engine Service, in order to generate UIs with appropriate adaptations included in this new UI.

Figure 7.1: AUI services model