validity - open questions are assumed to be more valid and this can be checked through face validity which is carried out by closely looking over the questionnaire and deeming what it is supposed to, a pilot study can also help with validity
Test - retest
used to check reliability of a study and involves replicating the study on the same Ps and comparing the results
Respondent bias
a researcher can simply ask Ps to be open, honest and truthful whilst answering the questions
Investigator effects
minimised in a variety of ways, e.g. having another researcher who checks the questionnaire in an impartial way
Strengths- Questionnaires
administered to a large group of people easily and quickly in comparison to interviews
can also be able to reveal more as Ps will reveal information about themselves anonymously
Weakness - questionnaire
Ps may complete their answers in a socially desirable way, which can decrease the validity of the results
Closed v.s. open
closed questions are easier to analyse as opposed to open questions, as the data obtained can be put into numbers, percentages and charts but open questions allow Ps to elaborate on reasons which can therefore produce a more detailed response
Interview types
structured - pre determined set of questions to ask
unstructured- no pre determined questions
semi structured - some pre determines questions and then follow up questions
Design issues - interviews
transcription of interview can be very tiring
interpretation of interview can be subjective, can be minimised by comparing 2 interviewers' analysis
develop a rapport to get them to open up - on sensitive issues, Ps are less likely to open up
investigator effects can be avoided by staying neutral, no leading or phrased questions
some Ps will open up to interviewers of a certain age/background which may influence the amount P says
Strength - interviews
qualitative which means that topics can be explored in depth and with detail
not constrained by a narrow range of answers
structured > unstructured in terms of reliability
Weakness - interviews
time consuming than a closed questionnaire
subjective analysis as interviewers own views could potentially damage the results