Looking for the Best: Identifying Exceptional Performers in Education and Elsewhere. TM Report 50.

To the data analyst, outliers can present both a problem and an opportunity. Stray or outlying observations can severly distort estimates of a distribution's central tendency (like the mean) and estimates of one variable's relationship to another (like the regression coefficient). These problems are frequent and serious, and as a result, increasing numbers of statisticians are developing new estimating procedures that are robust in the face of outliers. But outliers may also present an opportunity. An unusual servation may indicate the existence of a process not operating in the st of the distribution. In education, for example, an outlier may turner ut to be an unusually effective school, perhaps one worthy of emulation ' roughout the educational system. Finding the best by locating outlier ay be particularly important in the evaluation of public policies. Can one find exceptionally good police forces and study the causes for their success? What about outstanding rura?, development projects, exceptional hospitals, and unusally effective manpower training,;programs? Indeed, one may suggest a worthwhile general rule for piilicy evaluations: For exceptions to the general rules, include a search for unusual performers. (Author) Documents acquired by ERIC include many informal unpublished materials not available from other sources. ERIC makes every effort to obtain the best copy available. Nevertheless, items of marginal reproducibility are often encountered and this affects the quality of the microfiche and hardcopy reproductions ERIC makes available via the ERIC Document Reproduction Service (EDRS). EDRS is not reonsible for the quality of the original document. Reproductions supplied by EDRS are the best that can be made from the original. CI .E 1:11' IC: ERIC CLEARINGHOUSE ON TESTS, MEASUREMENT, & EVALUATION EDUCATIONAL TESTING SERVICE, PRINC ETON, NEW JERSEY 08540 TM REFAT 5C DECEMBER 1975 U.S. DEPARTMENT OF HEALTH, EDUCATIONS WIELPARE NATIONAL INSTITUTE OF EDUCATIONTHIS DOCUMENT HAS SEEN REPRO. DUCED EXACTLY AS RECEIVED FROM THE PERSON OR ORGANIZATION ORIGIN ATING IT POINTS O. VIEW OR OPINIONS STATED DO NOT NECESSARILY REPRE SENT OFFICIAL NATIONAL INSTITUTE OF EDUCATION POSITION OR POLICY OD. LOOKING FOR THE BEST: IDENTIFYING EXCEPTIONAL PERFORMERS IN EDUCATION AND ELSEWHERE*