validity

• Types of validity

  Validity - whether an observed effect is genuine and represents what is actually out there in the real world.

  Internal - control within the study

  External - generalising to other settings, population or eras

  Ecological - whether findings can be generalised from one setting to another, most particularly generalised to everyday life

  Temporal - findings should be consistent overtime
• Ways of assessing validity

  Face validity - a basic method to assess validity : does the test measure what it is suppose to ?. This is achieved by eyeballing the measuring instrument or by passing it to an expert to check.

  Concurrent validity - A new intelligence test. Their scores are then compaired with performance on a well established test
• Improving validity.

  Observations - Behavioural categories that are well defined (operationalised)

  Qualitative research - Interpretive validity shown through the coherence of narrative and direct quotes from participants. Triangualtion involves using a number of different sources as evidence.
• Improving validity.

  Experiments - control groups mean a researcher is more sure that changes is due to the DV were due to the effect of the IV. Standardised procedures and single/double blind procedures minimise the impact of participant reactivity and investigator effects.

  Questionnaire - lie scales control for the effects of social desireability bias