Activity 5

Reliability

So what do we mean by reliability? If a research tool is consistent and stable, and therefore, predictable and accurate, it is said to be reliable.

A scale or test is reliable to the extent that repeat measurements made by it under constant conditions will give the same result.

REFLECT: If you give out a questionnaire to a mixed ability year 7 class to find out about the reading habits of boys and girls and you find that only 25% of boys ever read fiction and then you send out the same questionnaire to another very similar mixed ability class of the same size in the same year group in the same school and you find that 60% of the boys regularly read fiction, could you say that the questionnaire was unreliable?

The wording of questions could be ambiguous. Different pupils might have interpreted the same question in different ways. You can never have a research tool which is completely reliable because it is impossible to control all the factors which affect reliability.

If you administer one questionnaire in a quiet school library early in the morning and the other in a noisy classroom last thing in the afternoon, the results could be different because the mood of the respondents is totally different.

WRITE: List some ways in which you could design and administer a questionnaire in order to minimise the possibility of such variation.

(Allow 15 minutes)