reliability

• reliability

  refers to the reproducibility or consistency of measurements
• external reliability

  measures how consistently a test produces similar results over repeated experiments or different conditions
• internal reliability

  how consistently different items within a single test measure the same concept
• ways of measuring reliability

  split half method

  test retest method

  inter observer reliability
• split half method (INTERNAL)

  split the test into 2 halves and compare results

  if scores are similar, internal reliability is high
• test retest method (EXTERNAL)

  administer the same test to the same participants on 2 different occasions and compare scores
• inter observer reliability method

  2 or more observers agree on categories

  carry out observation of the same participant individually

  they compare 2 or more sets of results

  there should be a high correlation (more than 0.8)