Self report: Reliability and Validity

The consistency between two different interviewers

Often more than one interviewer used to collect data for a study. Low reliability caused if interviewers behave differently. Can be assessed by comparing results from interviewers questioning same person. Data should be the same

A measure of whether something varies from one time to another i.e is consistant over time

A method of assesssing external reliability by giving the same psychological test to same participants on two occasions to see if same result is obtained.

The interval between test and retest must be long enough so that participants cannot remember previous answers but not too long as thoughts and feelings may change so their scores would be different

A measure of whether a questionnaire is consistant within itself

A method of assessing internal reliability

Test items are split into two halves and the scores on both halves compared. Scores should be similar if the test is reliable.

Concerns the extent to which the results can be generalised to other people and settings. 

Concerns whether a test does assess what its supposed to assess

Concerns the extent to which the results of a study can be generalised to other groups of people besides the participants who took part in the study

Concerns the ability to generalise a research effect beyond the particular setting in which it is demonstrated to other settings. In the case of a questionnaire/interview the issue is whether responses to questions on a topic actually represent the target behaviour

A researchers expectations and beliefs may encourage certain behaviours in participants. The result is researcher's expectations are fulfilled

Concerns whether the items om a test look like they are assessing what the researcher intended to assess

Concerns whether a test assesses the intedned underlying contruct

Can be established by comparing performance on a new test with a previously validated test on the same topic

Refers to the extent that test scores can predict a future behaviour or attitude