Reliability

• What does reliability refer to in measurement?

  Consistency in measuring outcomes
• What are the two types of reliability?

  Internal reliability and external reliability
• What does internal reliability measure?

  Consistency within the measurement method
• What would indicate a lack of internal reliability in a ruler?

  Variable centimetres on the ruler
• How could internal reliability be checked?

  Using the split half method
• What does external reliability measure?

  Consistency over time when repeated
• What would indicate a lack of external reliability in an IQ test?

  Different scores for the same person
• How could external reliability be checked?

  Using the test/re-test method
• What is inter-rater reliability?

  Consistency between two raters' responses
• How is inter-rater reliability assessed?

  By correlating ratings from each observer
• What are ways to improve reliability in questionnaires?

  • Test-retest process for correlation
  • Rewrite or deselect ambiguous questions
  • Replace open questions with closed questions
• How can reliability be ensured in interviews?

  • Use the same interviewer each time
  • Properly train interviewers
  • Use structured interviews with fixed questions
• Why are lab experiments generally reliable?

  • High control over conditions
  • Standardised procedures
  • Rigorous instructions for participants
• How can the reliability of observations be increased?

  • Properly operationalise behavioural categories
  • Ensure measurable and self-evident behaviours
  • Avoid overlapping categories
  • Create an exhaustive behaviour checklist
• What correlation value indicates a need for questionnaire revision?

  Less than 0.8+
• What is a potential issue with open questions in questionnaires?

  They may be ambiguous or complex
• How does a structured interview differ from an unstructured interview?

  Structured interviews use fixed questions
• What can reduce the reliability of a study in lab experiments?

  Not employing controlled conditions
• Why should behavioural categories not overlap in observations?

  To ensure clarity and avoid confusion
• What is the purpose of a behaviour checklist in observations?

  To ensure reliability of measurements