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Sample size needed for student ratings of instruction
Author(s) -
Mast TA,
Lange AL,
Patridge MI
Publication year - 1978
Publication title -
journal of dental education
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.53
H-Index - 68
eISSN - 1930-7837
pISSN - 0022-0337
DOI - 10.1002/j.0022-0337.1978.42.3.tb01168.x
Subject(s) - psychology , sample (material) , sample size determination , medical education , higher education , mathematics education , statistics , medicine , mathematics , political science , chemistry , law , chromatography
The number of evaluation forms students are asked to complete is multiplying. To reduce that number, the present study determines the minimum sample size needed for accurate student ratings of instruction. Typical questionnaire items using four‐ and seven‐category ratings scales were studied. Data for four class sizes (40, 60, 100, 140) were sampled in graduated sizes, and a standard error of the mean was computed for each sample size. A permissible error index was computed to estimate the accuracy of ratings obtained from any sample size needed for the four different class sizes. Figures are presented from which minimum sample sizes necessary for accurate student evaluation of instruction can be computed. The figures show that sampling only one‐third of classes of 100–140 students is sufficient to obtain accurate evaluations.