Validity

• internal validity


  the findings are accurate, and the effects on the DV are caused by the IV. Therefore, the study measures what it intends to measure (as confounding variables have been controlled and will not affect the results)
• external validity

  whether the study paints a true picture of real-life behaviours (e.g. if the tasks have mundane realism) and whether the findings would apply to different places, different times, or different people (population validity)
• mundane realism


  refers to whether the tasks are 'everyday' usual occurrences
• representativeness


  refers to how alike something is to something else. A diverse sample of participants, across different ages, genders and races could be considered representative and hence would have high levels of population validity (a type of external validity), because the sample is like wider society.
• location of psychological research

  can impact validity for example a lab does not reflect a real life setting
• specific validity issues


  refer to factors that jeopardise validity of research during the data collection phase. They impact both the internal and external validity of research-researcher bias-demand characteristics-social desirability bias
• researcher bias


  where the researcher either directly or indirectly influences the results of a study, either through the process of designing the study or through the way the research is conducted or analysed.
• demand characteristics


  a type of confounding variable where participants unconsciously work out the aim and act differently (either through social desirability or the 'screw you' effect*)(the 'screw you' effect is where participants work out the aims of the study and deliberately act in a way that will 'ruin' the results)
• social desirability bias


  participants give the response that they think will show them in the best possible light. This may mean that their responses are not a true reflection of their real thoughts/feelings.
• overcoming issues of validity


  using methods designed to overcome specific validity issues-the use of double-blind procedure-the use of single-blind procedure-changing the location/nature of the research tasks to make them more reflective of real life
• double-blind procedure


  -helps to overcome researcher bias-this means that neither the researcher collecting the data, nor the participant involved knows the true aims of the study, effectively preventing researcher bias as they don't know the aims and can't give hints or tips to participants.-it also reduces demand characteristics, where participants work out the aims and change their behaviour accordingly
• single-blind procedures

  • -helps to overcome social desirability and demand characteristics-this is particularly useful if the research design is repeated measures or the participants will be able to confersingle blind procedure involves the participants being unaware of the research hypothesis until after their role is complete-it differs from a double-blind procedure as the researcher knows the aims. Therefore, this does not overcome researcher bias.-alternatively, the use of independent groups would reduce these validity issues
• change to the location of the research and nature of the task

  can improve validity through ensuring that research is conducted in the field rather than the lab, or with realistic tasks that a person would normally complete in day-to-day life.
• assessing validity


  -face validity-predictive validity-content validity-concurrent validity-construct validity
• face validity


  -the least sophisticated measure of validity-face validity is simply whether the test appears (at face value) to measure what it claims, hence, it is subjective.-tests where the purpose is clear, even to naïve respondents (participants who do not know the aims of the study), are said to have high face validity.
• predictive validity


  the degree to which a test accurately forecasts a future outcome on a more broadly related topic. Do the findings apply in different and more varied situations?
• content validity


  -this objectively checks whether the method of measuring behaviour is accurate and decides whether it is a fair test which achieves the aims of the study (internal validity)-this can be carried out by asking an expert in that specific area of behaviour to check if the test is valid
• concurrent validity


  -validating a measurement by comparing it with an established one that has known validity-if similar results occur on both tests, then the new test has concurrent validity. If not, then the new test would have to be redesigned and carried out
• construct validity


  -the most sophisticated test of validity, as it looks at whether the overall results reflect the phenomena (external validity)-it is achieved by checking the existing definitions of the behaviour being studied and redesigning the test if it measures a different construct