week3-2_testing.ppt

Norms 01/18/24 1 Norms Norm= a person’s test score is compared to a group’s score. Norm-based interpretation Norms provide standards for interpreting test scores. 01/18/24 2 Norms Where should we get normative information from? Suppose, we have the raw scores of an entry-level secret...

Norms 01/18/24 1 Norms Norm= a person’s test score is compared to a group’s score. Norm-based interpretation Norms provide standards for interpreting test scores. 01/18/24 2 Norms Where should we get normative information from? Suppose, we have the raw scores of an entry-level secretary on a typing speed test. We could compare these raw data with... the scores of people in general?  the scores of experienced typists  the scores of other entry-level secretaries.  Standardization sample of the WAIS-IV consists of 2,200 with an age range of 16 to 90. 01/18/24 3 Norms Types of norms. Percentile rank=percentile Age norms: some psychological characteristics change over time, representative sample in age groups. Grade norms: school children 01/18/24 4 Percentile rank B= Boys, G=Girls 01/18/24 5 Age Norms Changes over time, changes systematically with age such as vocabulary, mathematical ability. 01/18/24 6 Age Norms For 60 months; 75th percentile rank is about 35 50th percentile rank is 28, 25th=18 01/18/24 7 Grade Norms Just beginning the 2nd grade, the median score is 22. GE= Grade Equivalent 01/18/24 8 Norms Cautions: A person’s scores should be compared to an adequate population. Normative data get out-dated quickly. Large sample needed for minimising sampling error. 01/18/24 9 Age and Gender Related Norms Tracking chart for boys’ physical growth from birth to 36 months. 01/18/24 10 Age and Gender Related Norms Tracking chart for girls’ physical growth from birth to 36 months. 01/18/24 11 Age and Gender Related Norms 01/18/24 12 Norms Setting standards & cut-offs: External standard rather than comparison to other test-takers (e.g. School grading)  When most students get F, you get DD. From normbased perspective, you’re fine but your absolute level of performance is quite poor! Criterion-referenced tests: compared to a criterion or set of standards. Need to separate fails and passes >cut-off score. How? Angoff method: an expert assesses each item & defines probability of barely competent person to answer correctly. 01/18/24 13