Reliability and Validity

• What is reliability in the context of a study?

  Reliability is achieved if a study shows that the independent variable (IV) affects the dependent variable (DV).
• What does it mean if a study is replicated and shows similar results?

  It indicates that the measure is consistent and not likely to fluctuate significantly.
• What is a standardised procedure in a study?

  A standardised procedure ensures that the study can be replicated and yields the same results.
• What type of experiments are considered the most reliable in psychology?

  Lab experiments are the most reliable method used in psychology.
• What are the characteristics of lab experiments that contribute to their reliability?

  • Conducted in a neutral space under controlled conditions
  • Follow a standardised procedure
  • Use random allocation of participants to conditions
  • Tend to use a control group for comparison
  • Generate quantitative data that is easy to compare and analyze
• Why are field experiments considered less reliable than lab experiments?

  Field experiments are subject to extraneous variables that the researcher cannot control.
• What makes natural experiments less reliable than lab experiments?

  Natural experiments use a naturally occurring IV that the researcher cannot control.
• What are the two types of reliability discussed in the study material?

  • Internal reliability: Consistency within the test itself
  • External reliability: Consistency of a test measure over time
• How can the reliability of a questionnaire be assessed?

  The reliability of a questionnaire can be assessed using the test-retest method and the split-half method.
• What does the test-retest method measure?

  The test-retest method measures external reliability.
• How is the test-retest method conducted?

  The same participants are given the same questionnaire at separate time intervals.
• What does the split-half method measure?

  The split-half method measures internal reliability.
• How is the split-half method conducted?

  The researcher splits the test in half and compares responses from both halves.
• What is inter-observer reliability?

  Inter-observer reliability is the consistency between two or more trained observers conducting the same observation.
• What steps are involved in ensuring inter-observer reliability?

  1. Agree on behaviour categories before observation
  2. Conduct observations separately to avoid conformity
  3. Compare independent data sets after the observation
  4. Test correlation between the data sets
• How can the reliability of lab experiments be improved?

  By controlling and standardising all aspects of the procedure.
• How can the reliability of observations be improved?

  By ensuring that behavioural categories are operationalised and distinct.
• How can the reliability of questionnaires be improved?

  By using the test-retest method and the split-half method to exclude inconsistent questions.
• How can the reliability of interviews be improved?

  By using the same interviewer for each interview and trained interviewers.
• What is validity in the context of a study?

  Validity is the extent to which the findings of a study are representative of real-life situations.
• What are the types of validity discussed in the study material?

  • Internal validity: Results due to manipulation of the IV
  • External validity: Generalisability of results beyond the research setting
  • Ecological validity: Real-life relevance of the task
  • Temporal validity: Relevance of findings over time
• What does internal validity measure?

  Internal validity measures the extent to which results are due to the manipulation of the IV rather than confounding variables.
• What does external validity measure?

  External validity measures the extent to which results can be generalised beyond the research setting.
• What is ecological validity?

  Ecological validity is high when the task aligns with real-life experiences.
• What is temporal validity?

  Temporal validity measures the relevance of research findings over time.
• What are the methods for assessing validity?

  • Face validity: Does the test measure what it claims to measure?
  • Predictive validity: Can the test predict future behaviour?
  • Concurrent validity: Do two tests of the same behaviour agree?
• How can the validity of lab experiments be improved?

  By ensuring controlled conditions and using a control group for comparison.
• What are investigator effects?

  Investigator effects occur when a researcher unintentionally influences the outcome of the research.
• What are demand characteristics?

  Demand characteristics occur when participants alter their behaviour due to awareness of the research procedure.
• How can demand characteristics be reduced?

  By disguising the aim of the study and using single or double-blind procedures.
• How can the validity of observations be improved?

  By using covert methods and ensuring clear, unambiguous behavioural categories.
• How can the validity of questionnaires be improved?

  By using a lie scale and reverse scoring to ensure consistent responses.
• What is the essence of ecological validity?

  • The task should feel real and natural to participants
  • It is not solely about conducting the study in a natural setting