Validity and Reliability

• What is validity in the context of psychological research?

  Validity is a measure of the truth of whether a test or experiment measures what it claims to measure.
• What does internal validity assess in a study?

  Internal validity assesses how much the findings of the dependent variable are related to the independent variable, excluding other factors.
• Can you provide an example of a situation where internal validity might be lacking?

  Participants responding to demand characteristics and acting as expected can indicate a lack of internal validity.
• What is external validity concerned with?

  External validity is concerned with whether results can be generalized beyond the study to other settings, populations, or eras.
• What are the two main types of external validity?

  • Population validity: Can results be generalized to the general population?
  • Ecological validity: Can results be generalized to real-world settings?
• What is the concept of lack of mundane realism in external validity?

  Lack of mundane realism refers to tasks that participants perform in a study that do not reflect everyday life, limiting the truth of the findings.
• What does temporal validity refer to?

  Temporal validity refers to whether the findings of a study or concepts of a theory hold true over time.
• Can you give an example of a study that lacks temporal validity?

  Asch’s research on conformity lacks temporal validity as it was conducted during a very conformist time in American history.
• What is face validity?

  Face validity is when an independent expert assesses whether a measure will measure what it is intended to measure.
• What is concurrent validity?

  Concurrent validity involves comparing a new procedure with a similar procedure that has already established validity.
• What indicates that a test has strong concurrent validity?

  A strong positive correlation of +0.8 between the new procedure and the established procedure indicates strong concurrent validity.
• How can validity be improved in experimental research?

  • Use a control group for comparison.
  • Standardize procedures to minimize effects of participants and investigator.
  • Implement single-blind and double-blind procedures to reduce demand characteristics.
• What are some ways to improve validity in observational research?

  • Minimize observer input, possibly using covert observations.
  • Ensure behavioral categories are specific, not overlapping, or ambiguous.
• How can validity be enhanced in questionnaires?

  • Include a lie scale to assess response consistency.
  • Ensure anonymity of participants' responses.
• Why might qualitative methods be considered more valid than quantitative methods?


  • They provide depth and detail that better reflects participants' realities.
  • Researchers must demonstrate interpretive validity, matching interpretations with participants' views.
• What is triangulation in research?

  • Triangulation involves using multiple sources of evidence, such as interviews, observations, and personal diaries, to enhance validity.
• What was Buss's research focused on regarding marriage partners?

  Buss researched what women and men look for in a marriage partner by analyzing over 10,000 dating advertisements across 34 countries.
• What type of validity might be assessed in Buss's research?

  The type of validity assessed in Buss's research could be external validity, as it involves generalizing findings across different cultures.
• What was the focus of the researcher interested in IQ levels across countries?

  The researcher administered a test involving students naming musical instruments to assess IQ levels in different countries.
• What type of validity might be assessed in the IQ levels research?

  The type of validity assessed in the IQ levels research could be external validity, as it involves generalizing findings across different countries.
• What was Ellison's research focused on regarding aggression?


  Ellison studied how aggressive people can become when their identity is hidden using a driving simulator with students.
• What type of validity might be assessed in Ellison's research?

  The type of validity assessed in Ellison's research could be internal validity, as it examines the relationship between the visibility of participants and their aggressive behavior.
• What is reliability in psychological research?

  Reliability is a measure of consistency in results when a test or measure is repeated.
• How is reliability assessed in psychology?


  Reliability is assessed by ensuring that a measure produces the same results each time it is carried out.
• What is external reliability?

  External reliability refers to the ability of a test to produce the same results each time it is administered.
• What is the test-retest method?

  The test-retest method involves administering the same test to the same participants at different times to assess reliability.
• What correlation coefficient indicates high external reliability?

  A high correlation coefficient of +0.8 indicates that the test is reliable.
• What is inter-observer reliability?

  Inter-observer reliability refers to the consistency of observations made by different observers in observational research.
• How can internal reliability be assessed?

  Internal reliability can be assessed using the split-half method, where a test is divided into two halves and the same participant takes both halves.
• What does improving reliability in questionnaires involve?

  Improving reliability in questionnaires involves using the test-retest method and ensuring a correlation coefficient of +0.8.
• How can reliability be improved in interviews?

  Reliability in interviews can be improved by using the same interviewer each time and training interviewers to avoid leading questions.
• Why are lab experiments often considered more reliable?

  Lab experiments are considered more reliable due to the control over variables and standardized procedures.
• How can observations be improved for reliability?

  Observations can be improved by operationalizing behavioral categories to ensure they are measurable and not overlapping.
• What are the key issues with reliability in psychological research?

  • Lack of replicability indicates unreliable results.
  • Changes in measurement over time can affect reliability.
• What are the methods for assessing reliability in psychological research?


  1. External reliability: Test-retest method.
  2. Inter-observer reliability: Consistency among different observers.
• What are the ways to improve reliability in psychological research?

  • Use test-retest for questionnaires.
  • Ensure consistent interviewers and training.
  • Conduct lab experiments with controlled variables.
  • Operationalize behavioral categories in observations.