Psychological Investgations AS

Where participants are asked a set of questions about themselves and to report answers. Using qestionnaires.

Strengths and Weaknesses of questionnaires:

• Quick and easy to complete and produce
• Easy to anayls closed questions
• Open questions can give qualitative data, their opinions
• Designed carefully, with a specific topic in mind
• Can send in the post, targets large amounts of people
• Boring to complete
• Demand characteristics and social desirability 
• Cost
• Needs alot of data to get good results
• Can be too personal
• People may not understand questions

Where participants are asked a set of questions about themselves and to report answers. Using Interviews.

Strengths and Weaknesses of interviews:

• In depth qualitative data
• More chance of an explanation
• Can follow up on particular questions
• More likely to spot a lier if you are a trained interviewer
• Harder to get participants
• Harder to analys as there is more qualitative data
• Social desirability
• More time consuming
• May need a trained interviewer to get answers from people

Refers to consistantcy of data measure. If consistant and we repeat the study, we should collect similar resiults.

• Test-re test reliability: take the self report on 2 seperate occasions. Then you can pair the scores using a correlation. If it is reliable, you should get similar scores and this should be a positive correlation. 
• Split half reliability: compare the scores form the 1st half of the questionnaire to the scores of the 2nd half of the questionnaire. They should be similar if the questionnaire is reliable.