SI chpt 5

the extent to which a measurement is consistent and free from erro

assures that a test is measuring what it is intendedto measure

"noise" that gets in the way of our finding the true score

predictable errors of measurement

errors due to chance and can affect a subject's score in an unpredictable way from trial to trial

a statistical phenomenon in which scores on a pretest are likely to move toward the group mean on a posttest becasue of inherent positive or negative measurment error; also called statistical regression

• yielded from a ratio of:
• (true variance) / (true score variance) + (error variance)

reflects the degree of association between two sets of data, or the consistency of position within the two distributions

used to establish that an instrument is capable of measuring a variable with consistency

when the test itself is responsible for observed changes in a measured variable

variation between two or more raters who measure the same group of subjects

the stability of data recorded by one individual across two or more trials

testing that is used as an alternative to test-retest reilability with paper-and-pencil tests, when the nature of the test is such that subjects are likely to recall their responses to test items

(homogeneity); reflects the extent to which items measure various aspects of the same characteristic and nothing else

a reliability measure of internal consistency based on dividing the items on an instrument into two halves and correlating the results

in generalizability theory, specific conditions under which reliability of a measurement can be generalized

the amount of change in a variable that must be achieved to reflect a true difference; the smallest amount of change that passes the threshold of error. Also called minimal detectable change (MDC)