1. Validity Review

2. Definition Does it (method/measure) measure what it is intended to measure? Does it (method/measure) measure what it is intended to measure? Internal Validity (was there a genuine effect?) Internal Validity (was there a genuine effect?) External Validity (can we generalise the findings?) External Validity (can we generalise the findings?)

3. Studies Poor Validity 1. Milgram (?) 2. Zimbardo 3. Tajfel 4. Loftus 5. Gould 6. Gardner & Gardner Good Validity 1. Piliavin 2. Rosenhan (?) 3. Samual & Bryant 4. Hodges & Tizard 5. Raine 6. Deregowski

4. Threats to Internal Validity Type 1 and 2 Errors. Type 1 and 2 Errors. Reliability to measures and procedure. Reliability to measures and procedure. Random errors. Random errors. Order effects/testing. Order effects/testing. Drop-out. Drop-out. Sample bias. Sample bias.

5. Threats to External Validity Construct validity Construct validity Mono-method bias. Mono-method bias. Demand Characteristics. Demand Characteristics. Researcher bias. Researcher bias. Generalisation to other populations. Generalisation to other populations. Ecological validity. Ecological validity.

6. Methods of Testing Validity Content/Face Validity. Content/Face Validity. Predictive Validity. Predictive Validity. Concurrent Validity. Concurrent Validity. Construct Validity. (Relates well to theory/expectations). Construct Validity. (Relates well to theory/expectations).

7. Issue It is easy to note that methods that are usually reliable are not always valid and that methods low in reliability are often valid. It is easy to note that methods that are usually reliable are not always valid and that methods low in reliability are often valid. It may be that much of human experience can not be studied in a restrictive scientific way to be valid. It may be that much of human experience can not be studied in a restrictive scientific way to be valid.