Learning SDP Concepts and Principles

Learning SDP Concepts and Principles

In the initial interviews, (McDermid and Ereback, 1994), section , subjects claimed that they wanted a better conceptual understanding of SDP and the object-oriented ideas that underlie SDP. Many complained that the method was too abstract, and very different from the previously used method at Ericsson (AXE-10). In the task analysis, (Bladh and Höök, 1995), in section , we saw that some of the queries posed by users revealed conceptual misunderstandings of SDP. Also the teachers on the courses in SDP given at Ellemtel, claimed that there were certain fundamental problems in learning SDP. All of these indications of difficulties in learning SDP led Klas Karlgren to perform a study on novices’ and experts’ understanding of SDP concepts and principles.

Karlgren’s starting point was to study subjects’ understanding of central SDP terms and principles, not how subjects follow SDP in their work. In part, we had already explored how users applied SDP in previous studies. Another reason to study users’ conceptual understanding had to do with the domain. The domain is a general software development method. As such it is not founded in any knowledge the learner may have about the ”real” world, instead the whole domain is abstract and learning it can be compared to a language game. By language game we understand seeing words as defined by how they are used rather than having proper definitions: language is defined through a negotiation process between those who try to communicate.

In SDP, as opposed to, for instance, physics, it is not always clear what the correct answers to questions are. In physics there are theories, grounded in observations of reality, that are conventionally considered to be the correct answers to the issues they cover. But SDP is more vague and not always so comprehensive as a scientific theory, simply because it is not a descriptive scientific theory but a development method. A question is in what way our POP system should convey the meaning of SDP-concepts and underlying principles.

The study was designed starting from a particular view on language: it is the use of words that will determine their meaning. The meaning of words, SDP terms and others, is not viewed as something abstract just grasped by the language user. It is essential that the language user is able to employ the word in correct ways for him/her to be said to have understood the meaning of the word.

Karlgren used the theories from Micki Chi and colleagues (1994) as a starting point. They analysed studies of people’s understanding of difficult concepts and then tried to formulate a theory that would explain why certain concepts are harder to learn than others and more often give raise to misconceptions. Their theory assumes that entities in the world belong to different ontological categories, such as MATTER (things) and PROCESSES. Conceptual change occurs when a concept is reassigned from one category to another. For example, if a learner first assumes that a whale is a fish, and then learns that a whale is a mammal, the learner has to move the concept whale from one category to another.

Micki Chi and colleagues are mostly concerned with what happens when a concept is first learnt as part of our ordinary everyday life, and then given a new meaning when learnt as part of a scientific theory. In particular, some concepts which are perceived as belonging to the MATTER category will turn out to belong to the PROCESS category, and this particular category shift is difficult to learn.

Method

Results

As SDP is abstract the domain did not easily lend itself to modelling into strict categories. Still, there were some distinctive differences between novices’ and experts’ understanding of SDP concepts and principles. Somewhat surprising, it was found that the novices’ understanding of the most fundamental concepts like object, process, object-oriented thinking, etc., was very fuzzy. On the other hand, understanding these terms and applying them correctly requires an operational understanding rather than being able to properly define the concepts.

For example, when asked to describe how many IEs there are in SDP, novices would have a confused understanding where they would not distinguish between IEs and instances of IEs that are produced as a result of applying SDP. In general, novices had problems with the distinction between instances of, for example, object types and the object types themselves. This is a crucial point in understanding any object-oriented method.

We can note that there are some studies which show that there is knowledge transfer that may both hinder and help the learner to move from a more procedural perspective on programming and design to the object-oriented view (Detienne, 1995; Pennington et al. 1995). In general, learning different programming paradigms might be difficult, and novices with different problem solving models will learn the new paradigm differently.

Conclusions for Design

In summary, the conclusion we draw from this particular study was that we must make it possible for users to ask specific questions about the fundamental SDP concepts. Also that we should not avoid those terms in the explanations but rather use them in their proper context. There is little we can do in order to help users obtain an operational understanding of these concepts: that can only be done through applying them. A good way is to provide examples where possible.

Directory: ~kia -> papers
~kia -> Usability and fun An overview of relevant research in the hci community
papers -> Comparing Two Approaches to Context: Realism and Constructivism
~kia -> B. Cahour (1), P. Salembier (1), Ch. Brassac (2), J. L. Bouraoui (1), B. Pachoud (3), P. Vermersch

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