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families and older generations. So the real question is, why have other console makers remained with the traditional interfaces and what will be the effects of this?
Now, where was I? Oh yes, right, I was talking about how a system can become more effective within existing system constraints ... So what exactly have we looked at this morning? Well, to sum up, we can group the ways in which the human and computer sciences help us understand HCI under three main headings. Firstly, by providing models of an engineering approach to human behaviour, the human sciences can help us to understand the interaction between human and system in a way which can be used for planning and quality assurance. However, the human sciences approach goes further, taking into account the broader context of the interaction between the individual and the system. Secondly, by modelling human systems as channels, for example the visual channel, it is possible to determine the effect of changes in the input and output of a system. The third major point is the need to consider the effect of limitations on available processing in both human and computer systems. These differences and similarities between the two approaches are reflected in the different ways in which the usability of a system can be evaluated …
Unit 9, Lesson 2, Exercise D≤2.7
1 Well, research has shown that there are three important areas where human sciences can contribute to HCI.
2 It could be argued that these three aspects also exist for the computer sciences.
3 But as we shall see, they tend to have a different emphasis – I’ll come back in a little while and tell you how they fit together.
4 From the point of view of system designers, it’s fair to say that it is cognitive psychology which provides tools for detailed approaches to interface design.
5 Increasingly, we find that modelling is used to provide evaluative tools to measure the quality of system interactions from the point of view of the user.
6 It’s true to say that measuring user satisfaction in this way is a very important aspect of modelling.
7 In terms of understanding how human cognition works, the Model Human Processor, or MHP, identifies three separate
systems, namely, perceptual, cognitive and motor systems.
8 So it should be clear that tools and techniques which draw on the human sciences are essential for system designers, and in particular for interface designers.
Unit 9, Lesson 3, Exercise A≤2.8 1 'visual, 'input, de'sign, 'haptic, 'output
2 mental 'model, 'user input, visual di'splay, 'input device, 'action sequence
3 'actually, 'generally, 'usually, i'deally, 'crucially
Unit 9, Lesson 3, Exercise C≤2.9
Part 3 OK, so moving on, … Now, let’s consider a question. How can we measure the effectiveness of the design tools? To do this, we need methods to test the usability of system interfaces. Just like the tools, the methods can be divided into two types – those which draw on the human sciences and those which draw on the computer sciences. Today I’m going to focus on three main evaluation tools which use the computer as a means of obtaining data on usability. These are heuristic evaluation, system logging, and eye tracking.
Let’s begin then with heuristic evaluation which is perhaps the most commonly used method. A website called
useit.com defines heuristic evaluation as “a method for finding the usability problems in a user interface design … by judging its compliance with recognized usability principles, in other words, the heuristics.” In practice, this involves a small group of evaluators, usually around six, each using a standard checklist to inspect the interface. They note down how each feature matches the items on the checklist. It’s important that the evaluators work independently, so that they don’t influence each other when making their judgements. However, their reports can be put together to provide one overall usability rating for the interface. This is a very simple method, but it can be a very powerful one. One possible drawback is that the method doesn’t involve the use of the interface in the way it would be used in ‘real life’, so some aspects may be missed out.
By the way, I see that some of you are using the Cornell note-taking system. That’s very good. Do you all know about this? No? Right, well, if you
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