Validity

• Validity 


  The ability of a test to measure what it is intended to measure
• Internal validity 


  extent to which we can draw cause-and-effect inferences from a study
• external validity 


  extent to which we can generalize findings to real-world settings
• Lack of internal validity in research

  occurs when there is bias - social desirability bias - where participants act in a more socially acceptable way to look good demand characteristics- participants figure out the aim of the stuffy and behave in a way that will support the researchers theory/ study investigator effects- where the resreachers consciously or unconsciously influences participants behaviour they can also be biased when interpreting participants behaviour and responses
• unconctrolled extraneous variables - lack of control not using standardised procedures not controlling participant variables by randomly assigning participants to groups this may effect the DV
• 


  Lack of external validity

  where study is not reflective of the real world and cannot be generalised across , time/ culture/ settings
• Ecological validity 


  extent to which results can be generalised to other settings
• Mundane realism 


  how closely a study mirrors real-life experiences
• Population validity 


  Generalizability of findings to broader populations.lead to gender or culture bias
• Temporal validity 


  the degree to which the results can be generalized across time
• Assessing validity 


  Face validity and concurrent validity
• Face validity 


  does the measured behaviour have face validity whether the test appears to measure what it claims to measure
• Criterion validity 


  the extent to which a measure is related to an outcome types concurrent and predictive validity
• Concurrent validity 


  the extent to which two measures of the same trait or ability agree
• Predictive validity 


  the extent to which performance on a test can predict future performance , outcomes
• Improving internal validity 


  improved by demonstrating high levels of control over variables to establish cause and effect relationship between IV and DV and not extraneous variables on DV. random allocation - controls participant variables standardised procedure- controls extraneous variables counterbalancing- controls order effects single and double blind procedures- controls researcher bias and demand characteristics peer review- controls researcher bias
• Improving external validity 


  improved by demonstrating that findings are generalisable replications ensures cause and effect relationships observed in the original study is not just limited to that one experimental/ observational set up. replicating findings in multiple settings improves ecological validity replicating findings In diverse groups of people improves population validity use diverse sample replicating historical studies improves temporal validity - modern day replication replicating findings using realistic tasks improves mundane realism