Throw the crutches away! Let the students walk! - Journal of Chemical

Oct 1, 1987 - End of chapter "crutches" (glossary of terms, performance objectives, chapter summary, and labeled problem sets) are more harmful than ...
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provocative opinion Throw the Crutches Away! Let the Students Walk! R. J. Tykodi Southeastern Massachusetts University, North Dartmouth. MA 02747 Take healthy persons and put them on crutches-you may, as a result, strengthen their arms and shoulders, hut you will certainly not get better walking or running from their legs. I have in mind general chemistry students, and the "crutches" I am worried about are the end-of-chapter features puffed by publishers of general chemistry textbooks: glossary of terms, performance ohjectives, chapter summary, laheled nroblem sets. Givine students these "crutches" tends to atrbphy important "m~scles" and hinders rather than helus the students'smooth "run through" the fields of chemAlbert Jay Nock, in his autobiography,' purports to see in human affairs the working of Epstean's Law: Man tends always to satisfy his needs and desires with the least

possible exertion. The presence of the above indicated "crutches" in a general chemistry textbook makes the working of Epstean's Law well-nigh inescapable. Glossary ot Terms and Chapter Summary The single best thing we can do to educate our students better is to make them write-sentences and paragraphs (not fill in the blanks). The act of writing organizes the information being urocessed and promotes thinking about the suhject matter.. General chemistw students should be required (a graded homework assignment) to construct in theirown words both a summary of each chapter covered in the course and a glossary of key terms for each chapter. If the textbook contains a glossary of terms and a summary for each chapter, the value of the student exercise (although not nil) is considerably depreciated: most students will simply paraphrase the book's glossary and summary rather than tackle the assignment afresh-Epstean's Law. Constructing a summary and preparing a glossary of terms for a chapter are activities just like solving problems and answering questions-they get the reader actiuely inuolued with the subject matter of the chapter; i t is such actiue inuoluement that authors and publishers should encourage in as many forms as possible-supplying end-of-chapter "crutches" is not the way to do it. Labeled Problem Sets When we meet "chemical" situations in dailv life (in industry, in the hospital, in the kitchen, in our~automobile, etc.), the situations do not comepre-labeled: "this is an acidbase situation," "this is an oxidation-reduction situation," "this i s . . ."-we first have to identlfy the type of situation

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Journal of Chemical Education

we are dealing with and then to mobilize our information about that sort of situation. Exam questions are usually uncategorized-the student has first to recognize the prohlem pattern and then to call on the appropriate routine for solving the problem. Our present modes of instruction in general chemistry by and large do not promote pattern-recognition skills: we spend much time in showing how to apply definitions, how to apply trends and rules, how to carry out the "algebraic" routines involved in stoichiometrv. in eauilibrium calculatiuns, in gas Inw ~alvuliitions,etc. \Ye spend little or no time in t r a r h i n ~how to recornire - the kind dvrohlem a student is faced wit< If the texthook has mainly labeled oroblems a t the end of the chapter, the student is denied exercise in pattern-recognition. Even if there are supplemental uncategorized problems at the end of the chapter, instructors wiil tend not to use them, but to select sufficient drill problems from the labeled sets-Epstean's Law again. Performance Oblectlves I have no quarrel with performance objectiues, provided that thev are out toeether hv the instructor. Constructine a catalog of periormance objekives for a chapter is a formof actiue involvement with the subiect matter of the chapter that should be encouraged-just iike the active involvement on the Dart of the student when preparing a chapter summary. If