Primary Reference Source
Loucopoulos P and V Karakostas (1995) System Requirements Engineering. McGraw Hill International.
Observational methods involve an investigator viewing users as they work and taking notes on the activity which takes place. Observation may be either direct, where the investigator is actually present during the task, or indirect, where the task is viewed by some other means such as through use of a video camera.
Typical Application Areas
Useful early in specification for obtaining qualitative data. This method is an alternative (non-involving) version of Contextual Inquiry. It is useful for studying currently executed tasks and processes. It has been extensively advocated in the past.
Allows the observer to view what users actually do in context. Direct observation allows the investigator to focus attention on specific areas of interest. Indirect observation captures activity that would otherwise have gone unrecorded or unnoticed.
Observing can be obtrusive and subjects may alter their behaviour due to the presence of an observer. Co operation of users is vital and so the interpersonal skills of the observer are important. Notes and video tape need to be analyzed by the note-taker which can be time consuming and prevents the task being split up for analysis by a number of people. If events or behaviours which occur at unpredictable intervals are of interest, this kind of observation can become extremely time-consuming.
Cost of use
Analysis usually takes 5 to 7 times the amount of time spent recording events unless a substantial amount of analysis is done in real-time, during off-peak moments. Indirect observation requires access to audio visual recording and playback equipment.
Costs of Acquisition
Observers require training and practice in order to take accurate and complete notes. Suitability for requirements engineering in Telematics:
Some partner experience (SINTEF, NPL, HFRG, NOMOS). Technique widely used in industry by HCI consultants, and portable video kits are popular.
How to get it - Widely documented in the literature.
Detailed description of method
Naturalistic Observation as a field method involves the following steps:
1.Establish objectives and information requirements. Should the coverage be in breadth or in depth? It is extremely important at this stage to find out what will happen to the end-product of this process, and therefore to tailor the whole process to the requirements of those who will receive the results.
2.Gain contacts and especially their co-operation with the process of Naturalistic Observation that you intend to carry out establish the times, places, and people who will be observed. Note that in some countries, the law may prohibit you from taking video films of people without their explicit written consent.
3.Decide on the recording technique you will use. Will you rely on hand-written notes (traditional), audio, or video and audio records? Note that the more complete your record, the longer it takes to analyze. It is useful to be able to make some kind of first-cut analysis during observation
4.Analyse, summarize, and report in relation to the objectives set out at the start.
Observation as an approach in a laboratory setting is instantiated quite specifically using the Laboratory Based Observation approach. A variation of single user observation is two-user observation where pairs of users are invited to work together and the above process is carried out on the pair. One of the 'users' in two-user observation may be a member of the design team, and this is particularly useful in situations where there may be an unstable prototype.
Primary Reference Sources
Rubin, J. (1994) Handbook of Usability Testing. John Wiley, NY.
Nielsen, J (1993) Guerilla HCI: Using discount usability engineering . In R Bias and D Mayhew (Eds) Cost Justifying Usability. Academic Press, Boston.
This is an approach to studying user behaviour in the laboratory, and may be used at practically any stage in the development process when there is a representation of the software that users can interact with. The book by Rubin is cited on account of its clarity of exposition, but this approach is documented in many sources. J Nielsen advocates an approach he calls 'discount usability engineering'.
Typical Application Areas
These approaches may be used at any stage in the process, although 'discount usability engineering' assumes the existence of a prototype that can stand on its own.
The method can be seen as an alternative to more extensive trials, which may take place later, prior to a release of a product.
If planning and preparation work is underestimated, results may be of little value.
Cost of use
Basic needs for this approach are paper forms for the observers, and equipment to show the interface on a screen or wall. This equipment could include an overhead projector, a computer screen, a barco, or a video based system with monitor. Optional materials needed would be a video camera to record the test session, log software and a computer with a simple data logging program.
Costs of Acquisition
This approach is public domain. The work of Rubin is particularly useful as a starting point.
Suitability for requirements engineering in Telematics:
This method deserves consideration as it directly involves end users. While it can be applied early in the design with a paper and pencil prototype, it also integrates well with Performance Measurement and other metrics oriented methods that can be applied at a later stage of the design.
Detailed description of method
For this approach to be successful it is crucial that thorough pilot testing be conducted by the investigator before introducing users into the lab. This pilot testing has a number of steps:
1.The description of the tasks
2.A simple test procedure with written instructions
3.A predefined format to identify problems
4.A debriefing interview guide
5.A procedure to rank problems
6.An estimation of the proportion of problems identified (optional step)
If pilot testing is underestimated then results may be of little value. This planning will identify usability goals. Roles may then be distributed within the design team, and planning for the test can be administered. The number of subjects needed is then estimated, and a written procedure is made, with at least one pilot test being performed. Useful results can be obtained with three or four users; some data gathering techniques may need larger user sample sizes in order to minimize bias.
Using the test material, realistic scenarios will be recorded, along with demonstrations and instructions. After the session, data may then be collected from the subjects using interviews and questionnaires. Once trials are run, data is analyzed, metrics (if any) are calculated, and problem severity is prioritized in an implications report.
Naturalistic observation is probably the basis of all other methods. Scientists must first observe the world before they can formulate hypotheses. Yet, even the simple process of observing is not that simple when it is used as a method of study.
In principle, one can conduct naturalistic observation nearly anywhere. There are some exceptions, however, for example, the naturalistic observation of human sexual behavior, or the observation of juries. You cannot observe a jury unless you happen to be one of the jurors. So, to study sex and juries, we need other methods.
Animals make natural subjects for naturalistic observation. A good example is Schaller's work with the mountain gorilla. When Schaller first started wondering about the behavior of gorillas, very little was known about them outside of their behavior in zoos. So, Schaller arranged to go to Africa to study gorillas. He soon discovered that gorillas were hard to find. Slowly, and with much effort, he began to see signs of their presence. He began to see where they had been eating and sleeping a few nights before. Then he was closer; their beds were hours old. One day, while sitting in a clearing, a group emerged all around him.
From then on, he was able to watch them closely. He gradually discovered a great deal about gorilla behavior, including the fact they did not like cameras pointed at them. Other investigators followed Schaller after his pioneering work, including Diane Fossey. She was later killed by local gorilla poachers; her story is told in the movie, "Gorillas in the Mist".
Humans also make good subjects for naturalistic observation. The behavior of second graders makes a good example. The answer to questions about what second graders are like can be found by naturalistic observation. To observe them, a scientist would arrange to go to a second-grade classroom. Some schools are set up with one-way mirrors, so in those cases, observation would be fairly easy. Most schools are not set up that way, so the second graders would know that they were being observed. That would, quite naturally, change their behavior, at least for awhile. It might take a week or two of observation before the second graders settled down and reverted to their usual behavior. Then, naturalistic observation could start.
Naturalistic observation is probably the best method around for the process of formulating new hypotheses. By becoming intimately familiar with subjects and their behavior, one can start to make hypotheses about them and their behavior. Those hypotheses can then be tested by other methods. We will cover those other methods soon. So, the notion that naturalistic observation is a good first step in science derives from its utility in formulating hypotheses.
There are problems with the use of this method. The main one is the issue of bias. Researchers are always going to bring preconceived ideas to a naturalistic-observation episode. Then, unwittingly, those preconceptions will shape the observations themselves. For example, you may think that second-grade boys are more vocal than girls, so you may pay more attention when you hear boys talking and shouting, but less when you hear girls doing the same. How can you deal with this problem?
One way to deal with the problem of bias is to have multiple observers. If you are the only one consistently to observe some behavior, then, maybe you are adding it to the situation, or, maybe the others just cannot see it. However, now you and the other observers could look for it more closely. Another way to deal with bias is to record the situation on film or videotape. Then, it can be analyzed repeatedly. Still another way is to have naive observers. You train observers, but you do not tell them why they are observing. Then, those observers will be less likely to see the situation in the light of the hypothesis.
So, naturalistic observation is a good first step in research; it is good for formulating hypotheses, but care needs to be used to control for bias.
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