Sunday, September 13, 2015

No, College Lectures Are Not "Unfair"

In her recent New York Times essay "Are College Lectures Unfair?" Annie Murphy Paul, a science writer, asks "Does the college lecture discriminate? Is it biased against undergraduates who are not white, male, and affluent?" She spends the rest of the essay arguing the affirmative, claiming that "a growing body of evidence suggests that the lecture is not generic or neutral, but a specific cultural form that favors some people while discriminating against others, including women, minorities, and low-income and first-generation college students." She cites various studies that find that "active learning" and "flipped classroom" pedagogical techniques lead to the biggest improvements in performance among the groups who do the worst in traditional lecture-format classes.

Unfortunately, while it may well be true that flipping the classroom (having students watch video lectures at home and using classroom time for problem-solving and discussion) and making learning more active (increasing low-stakes quizzes, which enhance memory for concepts) are excellent ideas—and I personally think they are—the argument that the use of lectures has anything to do with fairness and discrimination is simply erroneous.

Here's why. First, if one group of students tends to perform better than another under a particular instructional regime, then it is likely that any change that improves everyone's performance (as active learning does, according to studies cited by Ms. Paul) should benefit most the group that starts out doing worst. This is a simple function of the fact that grades have maximum values, so there is less room for improvement for students who are already doing well. If this point isn't clear, imagine a hypothetical educational intervention that leads to every student knowing the answer to five particular questions on a 100-question final exam. The best-prepared students would probably have known several of those answers absent the intervention, while the least-prepared students would have good chances of not not having known them. Therefore, the least-prepared students might gain as much as 4 or 5% on their final exam grades, but the best-prepared students might gain as little as 1 or 0%. This would narrow the achievement gap between those groups. Any intervention that results in more learning is likely to have a similar pattern of effects.

So active learning should be good for any students who start out doing worse in general, not just for minority, low-income, or first-generation students. As Ms. Paul notes, "poor and minority students are disproportionately likely to have attended low-performing schools" and get to college "with less background knowledge." Suppose you tried active learning in a school where the students were overwhelmingly the children of white, middle-class, college-educated parents. You would still expect the lowest-performers among those students to benefit the most from the improved methods. Likewise, the best-performing minority students should get less out of improved pedagogy than the worst-performing minority students. In other words, the value of active learning for traditionally underperforming groups of students has everything to do with the fact that those students have underperformed, and nothing to do with the fact that they come from minority groups.

Now to the question of whether older pedagogical approaches "discriminate" against those minority groups, as Ms. Paul says they do. According to the American Heritage Dictionary of the English Language, to discriminate is "to make distinctions on the basis of class or category without regard to individual merit, especially to show prejudice on the basis of ethnicity, gender, or a similar social factor." Teaching a course in an old-fashioned lecture format, though it may often be less effective than teaching in flipped or active formats, and for that reason may result in lower grades for some types of students than for others, makes no distinctions between classes or categories of people, and therefore cannot be a form of discrimination. Indeed, any inferior form of instruction should lead to wider differences between students who start at different levels.

Consider the limiting case: imagine a "form of instruction" that is no instruction at all: the professor never issues a syllabus or even shows up, but still gives the final exam at the end of the semester. Students who started out with the most "background knowledge" about the topic will still know the most, and students who started out knowing the least will still know the least. All pre-existing differences between ethnic groups and any other student groups will remain unchanged. On the other end of the instructional spectrum, suppose the professor's teaching is so perfect that every student learns every bit of the material: then there will be no differences between any groups, because all students will receive grades of 100%. Note that none of this concerns what groups the students are part of—it can all be explained entirely by the artifact of high-quality instruction benefiting poorer-performing students more than better-performing students. Therefore, Ms. Paul's essay uses the words "biased" and "discriminating" incorrectly, with the pernicious effect of accusing anyone who doesn't flip their classroom or give lots of quizzes of being prejudiced against minority students.

For what it's worth, I have been truly impressed by the growing body of research on the science of learning. I think it's one of the most exciting practical achievements of cognitive psychology, and I am trying to incorporate more of it into my own teaching. But I also believe that good, engaging lectures have their place, and may be more effective in some disciplines than others. To be clear, I have no objections to any of the research Ms. Paul cites in her essay. (Indeed, I have not even read most of that research, because what's at issue here is not the scientific results, but the meaning Ms. Paul ascribes to them. I've assumed that she described all the results accurately in her essay. If the researchers somehow managed to separate the effects of minority status and baseline knowledge or performance in their analysis of the active learning effects, Ms. Paul doesn't say anything about how they did it—and since that analysis would be the logical lynchpin for her claims of bias, discrimination, and unfairness, it is negligent to ignore it.) We have learned a lot about effective teaching methods, but none of it justifies the sloppy, inflammatory claim that lectures are "biased" and "discriminate" against students from minority, low-income, or nontraditional backgrounds.