reliability

Question 1

Reliability

Answer 1

refers to how consistent the findings from an investigation or measuring device are. A measuring device is said to be reliable if it produces consistent results every time it is used

Question 2

Test-retest reliability

Answer 2

a method of assessing the reliability of a questionnaire or psychological test by assessing the same person on two separate occasions.
This how’s to what extent the test (or other measure) produces the same answers i.e. is consistent or reliable

Question 3

Inter-observer reliability

Answer 3

The extent to which there is agreement between two or more observers involved in observations involved in observations of a behaviour.
This is measured by correlating the observations of two or more observers. A general rule is that if (total number of agreements)/(total number of observations) > + .80, the data have high inter-observer reliability

Question 4

Improving reliability - Questionnaires

Answer 4

• the reliability of questionnaires over time should be measured using the test-retest method.
  Comparing 2 sets of data should produce a correlation that exceeds +.80.
  A questionnaire that produces low test-retest reliability may require some of the items to be ‘deselected’ or rewritten. e.g. if some questions are complex or ambiguous, they may be interpreted differently by the same person on different occasions.
• one solution may be to replace some of the open questions with closed, fixed choice alternatives which may be less ambiguous

Question 5

Improving reliability - Interviews

Answer 5

use same interviewer each time
If this is not possible or practical, all interviewers must be properly trained so, e.g. one particular interviewer is not asking questions that are too leading or ambiguous.
This is more easily avoided in structured interviews where the interviewer’s behaviour is more controlled by the fixed questions

Question 6

Improving reliability - Experiments

Answer 6

Lab experiments described to be reliable because the researcher can exert strict control over many aspects of the procedure, such as the instructions they participants receive and the conditions within which they are tested.
precise replication of a particular method though rather than demonstrating the reliability of a finding.

Question 7

Improving reliability - Observations

Answer 7

behavioural categories have been properly operationalised, and that they are measurable and self evident.
categories should not overlap and all possible behaviours should be covered on the checklist

If categories are not operationalised well, or are overlapping or absent, different observers have to make their own judgements of what to record where and may well end up with differing and inconsistent records