Figure 6-2.  Traditional grading.  Figure 6-3.  Effective tests have six primary characteristics.  6-4  Reliability is the degree to which test results are consistent with repeated measurements. If identical measurements are obtained every  time a certain instrument is applied to a certain dimension, the instrument is considered reliable. The reliability of a written test is  judged by whether it gives consistent measurement to a particular individual or group. Keep in mind, though, that knowledge, skills,  and understanding can improve with subsequent attempts at taking the same test, because the first test serves as a learning device.  Validity is the extent to which a test measures what it is supposed to measure, and it is the most important consideration in test  evaluation. The instructor must carefully consider whether the test actually measures what it is supposed to measure. To estimate  validity, several instructors read the test critically and consider its content relative to the stated objectives of the instruction. Items that  do not pertain directly to the objectives of the course should be modified or eliminated.  A test is a set of questions, problems, or exercises intended to determine whether the learner possesses a particular knowledge or skill.  A test can consist of just one test item, but it usually consists of a number of test items. A test item measures a single objective and  calls for a single response. The test could be as simple as the correct answer to an essay question or as complex as completing a  knowledge or practical test. Regardless of the underlying purpose, effective tests share certain characteristics.  [Figure 6-3] 