ERIC Number: ED216043
Record Type: Non-Journal
Publication Date: 1981
Reference Count: N/A
Anomalies in Achievement Analyses.
Ligon, Glynn; Matter, Kevin
Six anomalies in achievement test scores encountered by the Austin Independent School District are described. These include crossing gaps with uninterpolated medians; total group median declines while all subgroups' medians rise; outlying total percentiles; percentile and grade equivalent growth antithesis; same grade equivalent earning a different percentile in each content area; and the median does not represent any group. Evaluators and researchers must know how to distinguish real achievement gains from artifactual gains resulting from anomalies such as those discussed in this paper. It is necessary to determine when an inconsistency is an error and when it is an explainable anomaly. When interpreting achievement test scores, interaction of types of scores such as percentiles and grade equivalents, shifts in student demographics, and non-normal distributions within groups being tested need to be carefully considered. The factors causing the anomalies and possible solutions are discussed. (DWH)
Publication Type: Reports - Descriptive
Education Level: N/A
Authoring Institution: Austin Independent School District, TX.