Definition: A property exhibited by a test that yields the same results over time


  • A test that provides consistent results when taken multiple times.
  • Same test! Same results!

Examples of Reliability


  • A person takes a test and gets an 86%. He takes the same test again and gets the same score the second time.
  • Taking a practice test for AP Psych more then once, and receiving an 80% each time.
  • John scores a 2100 on his SATs. He takes them again, and still gets a 2100.

You may ask.. what wouldn't be considered "reliable"?

  • You take a test and score 67%. You retake it without studying anymore or preparing any different and score a 93%.
  • You recieve a 84% on a standardized test the first time. You retest, preparing the same way, and get a 59%.

external image reliability.gif

See Also...