460 SCHOOL SCIENCE AND MATHEMATICS

^WHATS WRONG’5 TESTING OFLABORATORY TECHNIC

BY RALPH E. DUNBAR AND ROBERT COOPERDakota Wesleyan University, Mitchell, South Dakota

Diwoky and Lewis (1) report the use of drawings for stimu-lating interest in laboratory technic. Their drawings includedglaring mistakes that had been made by students working inthe laboratory, as well as other less obvious mistakes. Thesedrawings were then posted on the general chemistry bulletinboard for student observation and study. The authors reportthat better laboratory technic has been stimulated by thesedrawings. Condon (2) has prepared a series of ^What IsWrong?^ drawings which was used as the basis for a contest forhigh school and freshman students. We have prepared a similarset of drawings and have used them for testing laboratory tech-nic in inorganic chemistry classes. The tests in each case havebeen administered after the students have completed the cor-responding experiments in the laboratory. They can be used asa test of the information gained and retained, as well as properlaboratory technic of the student. Mimeographed copies of eachdrawing were given to each student during a regular class ortest period. Blank lines were provided and the students in-structed to list all mistakes in either the arrangement of equip-ment or chemicals used. They were likewise advised to indicatethe proper procedure where any mistake was present in thedrawing. A perfect score would necessarily include a completetabulation of all of both items. Other replies could be propor-tionately graded.Our experience in using these tests has indicated that there

is a relatively high correlation between the scores on these testsand the actual laboratory technic of students, as evidenced bytheir work in the laboratory. We have also found that begin-ning students generally score higher on items involving equip-ment than chemicals.

LITERATURE CITED1. Diwoky, Fred F., and Lewis, John R. ^’The Use of Drawings for Stimu-

lating Interest in Laboratory Technic,n Journal of Chemical Educa-tion, VI, pp. 1523-1524, September, 1929.

2. Condon, John J. "A Contest for High School and Freshman Students,"Journal of Chemical Education, VI, pp. 1785-1786, 2020-2021, 2262-2265, October, November, December (1929); VII, pp. 167-170,436-440, 661-665, 893-896, 1166-1168, 1402-1403, January, Febru-ary, March, April, May, June (1930).

LABORATORY TECUNIC