信度·分析.ppt

;§1 Theory of Reliability;;EXAMPLES Stanford-Binet Fifth Edition: full-scale IQ (23 age ranges), .97-.98; test-retest reliability coefficients for verbal and nonverbal subtests, from the high .7’s to the low .9’s. WISC-IV: split-half reliabilities for full scale IQ, .97 WAIS-III: average split-half reliability for full scale IQ is .98; .97 for verbal IQ; .94 for performance IQ Thurstone’s Attitude Scale: .80 - .90 Rosenberg’s Self-Esteem Scale(1965): α(.77 - .88); test –retest, .85; Errors— Inconsistent and inaccurate Effect;;;; Classical True Score Theory;CONCEPTION;TABLE 5.1 One Measure Data;;Reliability Coefficient;;§2 Sources of Random Errors;Sources from Tests Item sampling is lack of representativeness. Item format is improper. Item difficulty is too high or too low. Meaning of sentence is not clear. Limit of test time is too short.;;;§3 Estimates Reliability Coefficient;Test-retest Reliability Also called Coefficient of Stability, which refers to the correlation between test scores obtained by administering the same form of a test on two separate occasions to the same examinee group. TEST RETEST ;REVIEW CORRELATION ;Formula for estimating reliability ;Application Example;Answer: ;Transform of formula 5.3 (5.4) ;Quality of test-retest reliability: Estimates the consistence of tests across time interval. Sources of errors: Stability of the trait measured Individual differences on development, education, learning, training, memory, etc.. Unexpected disturbances during test administration.;;;;;;;;;Application Example Two alternate forms of a creative ability test administered ten students in seventh grade one morning. Table 5.3 shows the test result. Estimate the reliability of this test. Table 5.3;ANSWER: If use formula 5.4, then ;;