Validity The extent to which a study legitimately measures what it claims to measure
Internal Validity
External Validity
Overcoming Issues
Issues
Ecological validity - the extent to which findings of a study can be generalised to real-life settings, this is often a problem with laboratory studies
Population validity - the extent to which the findings of a study can be generalised to the target population or to alternative groups, this is usually an issue with small/biased sample groups
Design the study to be carried out in real-life settings (field/natural experiments)
Increase the sample size to 250 participants and upwards or carry out the study on different groups of people
Assessing Validity
Construct Validity - use a construct (theory/idea) to establish if a test is legitimate
Face Validity - the researcher looks at their test to see if it is measuring what it claims to measure
Concurrent Validity - compare the test in the study to one that is already seen as valid, by seeing if the participants perform similarly on both
Predictive Validity - the researcher makes predictions of the outcome of the test then compares it to the actual findings
Content Validity - use an independent expert to assess the content (measures) of the study
Overcoming Issues
Issues
Researcher Bias - a researcher's interpretations of behaviour or the way they set up the study may be biased to support their hypothesis
Social Desirability - participants will change their answers or natural course of behaviour in order to present themselves in more socially acceptable ways
Demand Characteristics - participants guess the aim of the study and change their natural course of behaviour in order to help the researcher obtain favourable results
The Test is Inaccurate - the measure used doesn't measure the desired behaviour (IQ test solely measuring mathematical ability)
Double-Blind Study - ensure the researcher collecting the data and the participants don't know the aim or hypothesis of the study, this restricts bias in interpretation and demand characteristics
Ensure Confidentiality - if the participants are believe that their behaviours or responses cannot be attributed to them they are more likely to be truthful
Single-Blind Study - don't inform the participants of the aim of the study or take measures to ensure they do not guess the aim of the study
Pilot-Study - ensure the test is accurate by trialling it with a focus group then consult with participants and make changes as needed