Advantages and disadvantages

An economical way of gathering data from a large number of people. If the questionnaire is well designed, then the results can be analysed easily, possibly by computer. Good questionnaires are difficult to construct.

There is no automatic mechanism for follow up or probing more deeply, although it is possible to follow up with an interview by telephone or in person if necessary. Postal questionnaires suffer from low response rates.

Appropriate situations

Questionnaires are most useful when the views or knowledge of a large number of people need to be obtained or when the people are geographically dispersed, for example, in a company with many branches or offices around the country or around the world. Questionnaires are also appropriate for information systems which will be used by the general public, and where the analyst needs to get a picture of the types of user and usage that the system will need to handle.

5.3.6 Remembering the techniques

For those who like mnemonics, these techniques are sometimes referred to as SQIRO—Sampling, Questionnaires, Interviewing, Reading (or Research) and Observation. This order has been chosen to make it possible to pronounce the mnemonic. However, this is not the order in which they are most likely to be used. This will depend on the situation and the organization in which the techniques are being used.

5.3.7 Other techniques

Some kinds of system require special fact finding techniques. Expert systems are computer systems which are designed to embody the expertise of a human expert in solving problems. Examples include systems for medical diagnosis, stock market trading and geological analysis for mineral prospecting. The process of capturing the knowledge of the expert is called knowledge acquisition and, as it differs from establishing the requirements for a conventional information system, a number of specific techniques are applied. Some of these are used in conjunction with computer-based tools.