validity

• internal validity is a measure of whether the results obtained are solely a result of the change in the variable being manipulated (i.e. by the independent variable) in a cause-and-effect relationship.
• if the change in the DV was influenced by any other factor than the IV, the findings lack internal validity
• External validity is a measure of whether data can be generalised to other situations outside of the research environment they were originally gathered in.
• social desirability bias is when participants hide their genuine opinions/behaviours and instead act or respond in a more socially acceptable way to 'look good'
• demand characteristics occur when participants are aware or think they are aware of the aim of the study and change their behaviour to support the theory or deliberately go against it
• Investigator effects occur when a researcher unintentionally, or unconsciously influences the outcome of any research they are conducting. The participant's behaviour could be influenced by the researcher using more positive body language/ tone of voice when participants behave as expected, supporting the theory. The researcher could also be biased in how they interpret responses.
• uncontrolled extraneous variables can cause a lack of internal validity
• ecological validity is the extent to which data is generalisable to the real world, based on the conditions research is conducted under and procedures involved.
• mundane realism is a type of ecological validity that is concerned with the extent to which the task/activities of a study are similar to the stimuli experienced in the real world
• population validity refers to how well the sample used can be generalised to the target population as a whole and how representative it is.
• Temporal validity is a type of external validity and refers to the extent to which the findings and conclusions of a study are valid when we consider the differences and progressions that come with time.
• Pilot studies are small-scale practice investigations, carried out prior to research to identify potential problems with the design or method.
• Sometimes a researcher has to use another person to play a role in an experiment/ investigation. This person is called a confederate or stooge.