2What does it mean?In pairs, think of how we use the words reliability and validity in everyday life.What do these words mean? Is there a difference between them or do they mean the same thing?
3ReliabilityWhen assessing the reliability of a study, we generally need to ask two questionsCan the study be replicated?If so, will the results be consistent?High vs low reliability
4Measuring Reliability Match the method of estimating reliability to the description (pg165)Test-Retest reliabilityIf the measure depends upon interpretation of behaviour, we can compare the results from two or more raters.If the results in the two halves are similar, we can assume the test is reliableSplit Half ReliabilitySplitting a test into two halves, and comparing the scores in both halvesIf the results on the two tests are similar, we can assume the test is reliableInter-Rater reliabilityThe measure is administered to the same group of people twiceIf there is high agreement between the raters, the measure is reliable
5Validity Control Realism Generalisability Realism vs Control Did the IV cause the DV?RealismDoes the experiment reflect real life?Mundane realismGeneralisabilityCan we generalise our results to the general population?Realism vs Control
6Types of Validity Internal validity External Validity What happens inside the study.External ValidityHow our results can be generalised beyond the studyValidity of psychological measuresHow well our methods of measurement actually measure what we intend
7Internal Validity Mundane realism Extraneous variables Task A and B Situational variablesParticipant variablesInvestigator effectsDemand characteristicsParticipant effectsTask A and BName the variablesWhat are the EVs and how could they have been controlled?
9Validity of psychological measures Operationalisation of variablesCan result in loss of validity
10Validity of psychological measures Content validityDoes the method used actually seem to measure what you intended?Concurrent validityHow well does the measure agree with existing measures?Construct validityIs the method actually measuring all parts of what we are aiming to test?Predictive validityIs our measure associated with future behaviour?
11Validity of psychological measures Complete tacks C, D and E.