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In this paper, an initial theory of online learning as online participation is suggested. It is argued that online learner participation (1) is a complex process of taking part and maintaining relations with others, (2) is supported by physical and psychological tools, (3) is not synonymous with talking or writing, and (4) is supported by all kinds of engaging activities. Participation and learning are argued to be inseparable and jointly constituting. The implication of the theory is straightforward: If we want to enhance online learning, we need to enhance online learner participation.

Computer-mediated communication (CMC) has been adopted in most e-learning settings. However, few research studies have considered the effect of different CMC. This study examined how and why synchronous communication affected participation in online discussions. Two online classes that participated in two asynchronous and two synchronous online discussions were examined. Actual and perceived measures of participation indicated that synchronous communication induced personal participation. which could be regarded as a complement to cognitive participation. Personal participation involves more intense interaction better supported by synchronous communication while cognitive participation is a more reflective type of participation supported by asynchronous communication. In synchronous discussions, the e-learners felt that they worked together and were not restricted to only discuss course content. This was likely to induce arousal and motivation and increased convergence on meaning, especially in small groups.

It is commonly argued that a key challenge for e-learning is to encourage learner participation. Even though this challenge has received increased attention by researchers, little effort has been put into developing a sound theoretical understanding of what online participation actually is and how it may be studied empirically. This paper examines the conceptions and research approaches that underlie research on online participation in e-learning settings. A classification scheme was iteratively developed and used when publications on the topic were reviewed. It was found that research is dominated by low-level conceptions of online participation, which relies on frequency counts as measures of participation. However, some researchers aim to study more complex dimensions of participation, such as whether participants feel they are taking part and are engaged in dialogues, reflected by using a combination of perceived and actual measures of participation. In conclusion, a definition of online learner participation that acknowledges its more complex dimensions, such as doing, communicating, thinking, feeling, and belonging, is proposed.

This paper presents a user interface to the User-Centred Knowledge Model (t-UCK). T-UCK is a knowledge modelling tool for designing knowledge-intensive systems. The model centres round the various users, i.e., both the design users and the end users, and facilitates the use of a conceptual model for handling different types of knowledge, the reasoning strategy and other functionality. For the design users, the conceptual model is presented through a modelling view of the contents used for developing the system. For the end users, the conceptual model has a parallel consulting view used for sessions with the system. Both these views are directly modelled into the system through a graphical modelling language, the Unified Modelling Language (UML). UML is a general-purpose modelling language, which in a modified form it can be used for development of knowledge-based systems.

The thesis describes steps taken towards using graphic representation and visual modelling support for the knowledge acquisition process in knowledge-based systems – a process commonly regarded as difficult. The performance of the systems depends on the quality of the embedded knowledge, which makes the knowledge acquisition phase particularly significant. During the acquisition phase, a main obstacle to proper extraction of information is the absence of effective modelling techniques.

The contributions of the thesis are: introducing a methodology for user-centred knowledge modelling, enhancing transparency to support the modelling of content and of the reasoning strategy, incorporating conceptualisation to simplify the grasp of the contents and to support assimilation of the domain knowledge, and supplying a visual compositional logic programming language for adding and modifying functionality.

The user-centred knowledge acquisition model, proposed in this thesis, applies a combination of different approaches to knowledge modelling. The aim is to bridge the gap between the users (i.e., knowledge engineers, domain experts and end users) and the system in transferring knowledge, by supporting the users through graphics and visualisation. Visualisation supports the users by providing several different views of the contents of the system.

The Unified Modelling Language (UML) is employed as a modelling language. A benefit of utilising UML is that the knowledge base can be modified, and the reasoning strategy and the functionality can be changed directly in the model. To make the knowledge base more comprehensible and expressive, we incorporated visual conceptualisation into UML’s diagrams to describe the contents. Visual conceptualisation of the knowledge can also facilitate assimilation in a hypermedia system through visual libraries.

Visualisation of functionality is applied to a programming paradigm, namely relational programming, often employed in artificial intelligence systems. This approach employs Venn-Euler diagrams as a graphic interface to a compositional operator based relational programming language.

The concrete result of the research is the development of a graphic representation and visual modelling approach to support the knowledge acquisition process. This approach has been evaluated for two different knowledge bases, one built for hydropower development and river regulation and the other for diagnosing childhood diseases.

In knowledge engineering, modelling knowledge is the process of structuring knowledge before implementation. A crucial part of system development depends on the acquiring and structuring, since the quality of system’s contents is of decisive importance for making good decisions. Models are needed to assure that all the required knowledge is present. However, the current models tend to be large and this makes it hard to get a grip on the knowledge presented by the model. Also, many models are difficult to use and the users have to be experts on the models before using them. To avoid these problems, we introduce the User-Centred Knowledge Model (t-UCK) for modelling knowledge. The model supports different users, i.e., domain experts, knowledge engineers and end-users, to model, implement, test, consult, and educate through the use of graphic representation and visualisation.

Many problems in business, industry, and academia can be modelled as constraint programs consisting of matrices of decision variables. Such “matrix models” often have symmetry. In particular, they often have row and column symmetry as the rows and columns can freely be permuted without affecting the satisfiability of assignments. Existing methods have difficulty in dealing with the super-exponential number of symmetries in a problem with row and column symmetry. We therefore propose some ordering constraints which can effectively break such symmetries. To use these constraints in practice, we develop some efficient linear time propagators. We demonstrate the effectiveness of these symmetry breaking ordering constraints on a wide range of problems. We also show how such ordering constraints can be used to deal with partial symmetries, as well as value symmetries.

As the financial sector has become increasingly digitized, its vulnerability to cyberattacks has increased. Distributed Denial of Service attacks are one of the biggest threats on the internet today and has been growing steadily for the last few years. The increase applies to both the size and frequency of the attacks. DDoS-attacks have been a threat especially towards banks and therefore it is important to have a well functional cyber security strategy to withstand the attacks. This thesis investigates Swedish banks perception regarding the threat picture of DDoS-attacks against banks. As a result of a qualitative case study, Swedish banks opinion has been investigated through interviews with IT security managers at Swedish banks. The banks are considered to have effective strategies to prevent and manage DDoS-attacks but the threat of cyber attacks continues to increase. The participants mention various factors that show an increase in DDoS-attacks and the media can be an influence. The empirical material is analyzed using the National Cybersecurity Strategy (NCSS) framework developed by the European Union Agency for Cybersecurity (ENISA). 

Although many organizations have started to experiment with online communities, there is little theoretically grounded knowledge on how to develop, manage and improve such communities. In addressing this gap, we explore how participation in organizational online communities can be framed with the purpose to identify future research challenges. By conceptualizing the online community phenomenon the paper reflects on what motivates people and organizations to participate in such communities. Special attention is given to organizational online communities and potential research areas. A number of imminent research challenges are suggested.