B24 t043 good_tests


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B24 t043 good_tests

  1. 1. B24-T043 Testing and Evaluation Qualities of Good Tests B24 T043 Testing and Evaluation
  2. 2. Content Validity● Degree to which a test measures what it is supposed to measure● Every test item related to the stated performance objective● Must measure the degree of behavior change sought B24 T043 Testing and Evaluation
  3. 3. Things that affect validity● Manner in which the test is administered● Physical and emotional condition of test takers● Long detailed instructions test reading ability as much as learning● Standardized tests are often not valid for the group or for the objectives they are intended to B24 T043 Testing and Evaluation measure.
  4. 4. Construct Validity● Based on how the test is constructed● Could a clever student pass the test with out knowing the course material?● Could capable students fail just because they can’t determine what the test is asking for?● Is the test measuring reading ability, memorization skills, reaction B24 T043 Testing and Evaluation time, vocabulary emotional
  5. 5. Concurrent validity● Measuring your test against some predetermined criterion of validity.● Like a calibration test● Compare the results of a new test with those of an older test that is known to be valid.● Not often used in regular classrooms B24 T043 Testing and Evaluation
  6. 6. Ensuring Validity● Subjective method; Does it measure what it is supposed to measure.● Submit the test to competent practitioners● Critical inspection by test constructor● Reliability, objectivity, discrimination, comprehensiveness, and practicality contribute to B24 T043 Testing and Evaluation validity.
  7. 7. Reliability● Degree to which the test gives consistent results each time it is used.● Test should be long enough to provide thorough coverage of material● Elements that increase the chances of guessing should be eliminated B24 T043 Testing and Evaluation
  8. 8. Reliable but not valid● The test might reliably test a element which was not the intended variable● A thermometer reliably measures temperature but can’t be used to measure blood pressure.● A test must be reliable to be valid but it is possible for it to be reliable but not valid B24 T043 Testing and Evaluation
  9. 9. Ensuring reliability● Reduce the factors that vary each time the test is administered.● As many variable factors as test takers● Use Equivalent Forms method● High scorers on test #1 should score high on test 2 (measured by coefficient of correlation) B24 T043 Testing and Evaluation
  10. 10. Coefficient of correlation● How much one item( score is related to another)● Statistical expression● 1 expressing a perfect relationship and 0 expressing no relationship B24 T043 Testing and Evaluation
  11. 11. Ensuring reliability● Test- Retest method● Give the same test a second time● Assumes students don’t remember first test and that no learning has occurred in between tests● Use coefficient of correlation B24 T043 Testing and Evaluation
  12. 12. Ensuring reliability● Split Half method● Make a test● Separate the odd and even numbered questions● Administer as 2 tests and determine correlation B24 T043 Testing and Evaluation
  13. 13. Other means of improving reliability● Increase the overall length of the test● Improve clarity of items● Make directions clear and concise B24 T043 Testing and Evaluation
  14. 14. Objectivity● The degree to which the test items can be misinterpreted by the test taker● The degree to which the test can be scored with out bias or personal opinion affecting grades● Affects validity and reliability B24 T043 Testing and Evaluation
  15. 15. Scoring bias affects objectivity● Several competent people should be able to score the same test and get the same result● a problem for essay or project type evaluation instruments● Use a guideline or a rubric to reduce bias B24 T043 Testing and Evaluation
  16. 16. Objectivity is affected by student interpretation● Each question should be able to be interpreted in only one way by students who know the material well● Ambiguous or inconsistent questions add confusion● Poor grammar and sentence structure leads to misinterpretation B24 T043 Testing and Evaluation
  17. 17. A Discriminating test:● Identifies the students who have mastered the material from those who have not.● Has a wide range of scores when administered to a varied group of students● Should include items at all levels of difficulty● Items can discriminate in a negative direction when the poor students all get it B24 T043 Testing and Evaluation right
  18. 18. A comprehensive test● Has an appropriate number and type of items● All objectives and phases of instruction are covered in the test● Subjectively determined B24 T043 Testing and Evaluation
  19. 19. Practicality● Is the test usable● Is it readable, easy to administer and score● How much time money and personnel are required B24 T043 Testing and Evaluation
  20. 20. Discussion● Can you think of a test that is reliable but not valid?● How can the type of test affect validity?● What do you do to ensure that tests are administered in a consistent fashion? B24 T043 Testing and Evaluation