Self Report Methods

Questionnaires

A questionnaire is a set of written questions which are usually highly structured.  The researcher will normally assemble a number of questions which are then posed to a representative sample of the relevant population.  The questionnaire can either be highly structured, with fixed alternative responses which can then be collated and analysed, or more open-ended, with the respondents able to express themselves in their own words.

There are four main ways of administering questionnaires:  face-to-face interviewing, which is useful but expensive in terms of employing and training interviewers; handout questionnaires, when there is a readily available and clearly defined population who are all located in one place at a given time: postal questionnaires; and telephone questionnaires.

Response rates to questionnaires vary with the type of sample and with the population concerned.  A population which is highly motivated and interested in a topic will obviously produce a higher response rate than one which lacks interest.  The technique used to administer the questionnaire will also produce variation in response rate, with responses to postal questionnaires being the lowest and responses to telephone questionnaires being the highest.  There are also some factors which have been shown to increase response rates, such as using follow-up queries, providing incentives to respondents (such as a prize draw or free ball-point pen) and, most importantly of all, increasing the ease of reply.  As a general rule, the harder a questionnaire is to answer, the lower the response rate will be.

Strengths

1.         Surveys are able to study large samples of people fairly easy.

2.         Surveys are able to examine a large number of variables.

3.         Survey research can ask people to reveal behaviour and feelings which have been experienced in real situations.

4.         If samples of people are selected at random and are large enough it should be possible to generalise the results to a larger population.

5.         Questionnaire surveys can be carried out relatively cheaply.

Weaknesses

1.         People may not respond truthfully, either because they cannot remember or because they wish to present themselves in a socially acceptable manner. 

2.         We can not establish cause and effect relationships from survey data as other variables which could have had an effect may not have been considered in the questionnaire or interview.

3.         It may be difficult to obtain a random sample of the population because some people who are selected refuse to answer questions or it may be difficult to obtain a full list of the population from which to select a random sample.

4.         Whether the method is open-ended or highly structured, there can be difficulties.  In the case of the highly structured questionnaire, the structure will probably reflect the preconceptions of the compiler, and may force respondents to answer in a way which does not entirely accord with their views.  A more open-ended survey, on the other hand, may lead to much more subjectivity when it comes to its interpretation.  Of course surveys deal with people's verbal responses to questions posed verbally, as well as with behaviour.  There is no way you can be certain that what people say they do accords with what they actually do. 

Psychometrics

Psychometric tests are instruments which have been developed for measuring mental characteristics.  Psychological tests have been developed to measure a wide range of things, including creativity, job attitudes and skills, brain damage and, of course, 'intelligence'.   Psychometric means, literally, measuring the mind and, in one sense, any systematic attempt to assess mental characteristics could come into this category. The term, however is usually used to describe specific tests for personality, aptitude, intelligence or some kind of attitude measurement. 

Strengths

1.         This technique, of course, provides lots of quantitative data which is easy to analyse statistically.

2.         Psychometric tests are usually easy to administer.

Weaknesses

1.         Constructing valid and reliable tests is very difficult.

2.         Tests usually contain culture bias, especially intelligence tests.

3.         Most tests will contain designer bias, in the sense that any test is biased in the direction of the author's view.

4.         Most tests make the assumption that characteristics to be measured are fixed and invariant, both in relation to time and also in relation to circumstance or situation. Many studies in psychology, especially social psychology, demonstrate that this is not so. 

Interviews

There are many different ways to conduct an interview, ranging from casual chats to formal, standardised, set questions which have to be asked in a particular way.  Clinical interviews are lengthy interviews aimed at a detailed understanding of a person's mental processes.  There are no set questions; the questions depend on the last answers given. 

Strengths:

1.         Interviews conducted in a casual manner provide information that is more spontaneous and realistic than those obtained in a formal interview.

2.         If we use standardised interviews it is easier to generalise (as long as the sample is large enough).

3.         Clinical interviews provide insight into the thoughts of individual children or adults which a standardised format would not allow.

Limitations:

1.         Sampling of subjects is a problem (see section on sampling for more

            detail).

2.         Informal interviews do not allow generalisation.  One person may talk about something so differently from the way that another person does that it becomes almost impossible to compare what two people said.  This applies to some extent to clinical interviews.

3.         In formal interviews, if people feel that they are being asked a set of routine and automatic questions from a list they often do not talk as freely as they would in a casual conversation.  The interviewer needs to be thoroughly skilled and trained to make it seem a natural and not an awkward situation.  This means that a formal interview study is quite difficult (and expensive) to conduct well.

4.         A major problem with interviews is demand characteristics.  This includes interviewer biases and response biases.  An interviewer may influence the respondent through, for example, leading questions or subtle reinforcements of 'right' or 'wrong' answers.   Response bias may happen when, for example, respondents give socially acceptable answers.