RM- Types of validity Flashcards
What is internal/experimental validity?
Internal validity is a measure of whether results obtained are solely affected by the independent variable and not some other factor
What factors can reduce internal validity?
Investigator effects, demand characteristics, confounding variables, social desirability bias, lack of operationalisation
What are investigator effects?
When the characteristics of the researcher can affect the participants and the outcome of the research
What are demand characteristics?
When participants guess the aim of the study and change their behaviour.
What are confounding variables?
Extraneous variables that vary systematically which might have an effect on the DV.
What is social desirability bias?
When participants might try to portray themselves in a positive light and behave in an unnatural way which will affect the DV and the results gained.
What is lack of operationalision?
Variables have not been yet defined and measured properly. This could affect results overall resulting in low internal validity.
How can we use CONCURRENT VALIDITY to ASSESS INTERNAL VALIDITY?
- This is a way of establishing the internal validity of a new test whereby the scores gained from this new test can be compared against an older, established test where the validity is already known.
- If scores from both tests are similar and a positive correlation coefficient of +0.8 or greater is found, then the new test is judged as having high internal validity.
How can we use FACE VALIDITY to ASSESS INTERNAL VALIDITY?
- This is a way to measure whether the test or measuring instrument is measuring what it should e.g a questionnaire.
- One or more researchers/experts in the field can examine the test items/questions to see whether they are measuring what it sets out to do.
- They would do this by looking at the questions on a questionnaire and seeing, “on the face of it” whether the questions appear to be measuring what they should.
- E.g if we were to measure IQ, we could get a specialist psychologist in the field to examine each question in the IQ test and see whether each question is really measuring IQ or not.
How can we use CONCURRENT VALIDITY to IMPROVE INTERNAL VALIDITY?
If low concurrent validity is found on a questionnaire, then the researcher could remove questions that seem irrelevant or ambigious, and then test the concurrent validity again.
How can we use FACE VALIDITY to IMPROVE INTERNAL VALIDITY?
Face validity can be improved by an expert in the field examining all of the questions on the questionnaire. They might decide that some of the questions are not a good measure of the topic being investigated e.g IQ and then they might improve/rewrite/re-word certain questions again. This will help improve face validity.
How can we reduce investigator effects?
Double blind method where the investigator who deals with the participants also doesn’t know the aim of the study.
How can we reduce demand characteristics?
Use of deception- It may reduce likelihood that participants are able to guess the hypothesis of experiment causing them to act naturally.
What is external validity?
External validity is a measure of whether data can be generalised to other situations outside of the research environment they were originally gathered in.
What are the two key types of external validity?
Ecological validity and temporal validity
