Students' bubble sheets may be equally invalid in assessing teaching ability if the questionnaire asks students to rate surface characteristics of one kind of good teaching—like "returns papers promptly" and "leads discussions"—without allowing students to give a holistic assessment.

The use of such questionnaires distorts teaching. When an institution uses a multiple-choice test to evaluate students' writing, professors tend to drill their students in taking that kind of test, instead of giving them practice in writing. Similarly, when professors' careers depend on getting high scores on student evaluations of particular behaviors, professors will tend to adopt those behaviors whether or not they are appropriate to a particular subject or teaching style.

One recent development in both writing assessment and teacher evaluation is especially encouraging. Portfolio assessment has begun to make inroads in both areas as a more flexible and responsible form of measurement. Portfolios of students' writing or of teachers' syllabuses, exams, assignments, and statements of teaching philosophy can be evaluated holistically, when a single score or rating is all that is needed. But they can also receive much more detailed (and expensive) analyses, should the purpose of the evaluation be to improve the writing or teaching.

As with assessments of students' writing, evaluations of professors' teaching ought to be designed to meet specific goals of the assessment—either measuring overall teaching ability for tenure and promotion committees, or identifying ways to improve particular aspects of teaching for the professor. Colleges and universities now put a great deal of energy and expense into elaborate bubble sheets that serve nobody's ends well. Instead, institutions should devote their efforts to producing holistic information for administrative purposes, and detailed analyses of their performance for the teachers' own use. If that happened, we might actually see systematic improvement of college teaching—which is supposed to be the goal of the entire operation.