want to know more about it, I suggest you look at How to study in college by Walter Pauk, the 9th edition, published in 2007. It’s very good, and it should be in the university library. I’m sure that you all know the importance of taking good notes – and this system is particularly useful.
The second computer-based method of testing
the usability of an interface is system logging. Now, we already know that it’s important to be able to identify exactly where problems occur in carrying out a task. System logging is particularly useful for this because it can provide actual data on the user’s interactions with the interface. This means it can indicate whether or not an action sequence has led to the achievement of a goal. System logging can also show any tasks which the user was unable to complete. However, basic system logging does not identify the reason for failure. In fact, as Dix points out in Human computer interaction, one of your core texts – the 3rd edition, which was published in 2006, we can only rely on system logs to tell us what has happened, not necessarily why it has happened. A more advanced form of system logging is video logging. This creates a video of users’ interactions with the interface, showing the actions of the user and how they tried to complete the task. While it can show how the user failed, it still doesn’t provide the reason why – which could be two very similar icons, a confusing label or a hidden tab, for example.
The third method is eye tracking. This can be used along with a system logging method. It can provide even more detailed information on the user’s behaviour as they interact with the interface. In eye tracking, the user is provided with a headset which can measure the point of gaze. This simply means where the individual is looking. We can use this device to gather data that can be collected on the point of gaze, which can show the choices a user considered before deciding on a particular action. This in turn gives a better understanding of the user’s mental processes. Eye tracking can also be used separately from system logging, for example to determine how a user’s attention is drawn to various parts of an interface. This can be used to identify distracting elements of interface design. Eye tracking can help bring us closer to what the user is thinking, as opposed to simply measuring their behaviour.
OK, so now we can see that these three different testing methods gather data on the usability of an interface, without actually asking users for information. In the first method, heuristic evaluation, the likely views of a user are
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represented by a checklist which an evaluator then uses to test the interface. In the second method, system logging, actual data on the user’s behaviour as they interact with the interface is gathered. However, there is no data on what the user is thinking or how they feel as they are interacting with the interface. The data collected by the third method, eye tracking, covers the whole period of time the user is interacting with the interface, not just while they are trying to complete a task. This means that it can be used to give some indication of what the user is thinking during the interaction. However, while behaviour-based data is valuable, it must not be the only way of gathering usability information. To quote Dix from the same text as before, “analytic and informal techniques can and should be used”.
Now I think that’s all I’m going to say for the moment on the computer-based methods of usability evaluation. Are there any questions so far? (Pause) No, good. Now when I see you in tutorials, we’ll look in more detail at the human sciences component of HCI. In the meantime, I’m going to set you a research task. Right, now listen carefully ... your task is to find out more about the methods of evaluating the usability of interfaces which draw on the human sciences. I’d like you to work in groups of four. Each group should find out about the various methods that are used and report back on your findings.
Unit 9, Lesson 3, Exercise D≤2.10
Extract 1 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.”
Extract 2
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 want to know more about it, I suggest you look at How to Study in College by Walter Pauk, the 9th edition, published in 2007. It’s very good, and it should be in the university library.
Extract 3
System logging can also show any tasks that the user was unable to complete. However, basic system logging does not identify the reason for
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