To Err Is Human; It's Also a Teaching Tool

July 22, 2005

Some years ago, after I had filed the grades for a large lecture course, one student -- a loyal attendee and diligent note taker -- dropped by my office to thank me for a great semester. After some pleasantries, she produced a typed note and said, "Oh, by the way, professor, here is a point I caught where you were wrong."

I blinked, thanked her, and promised I would check on the matter. After she left, I consulted some media-history texts and discovered to my horror that, contrary to what I had informed 250 undergraduates, Thomas Edison's first sound-recording device, his phonograph, consisted of tinfoil wrapped around not a wax disk but a metal cylinder.

I considered what my response should be. Obviously I should contact the student and tell her that she was indeed correct. But what about the rest of the class? Did admitting my error matter when the fact involved was, after all, trivial? The textbook did have the facts right. And what about the belatedness of any correction I might make?

After some internal debate, I decided that a higher principle was at stake: Even though the semester was over, I had one more lesson to teach my students. Admitting that you goofed is the right thing to do, no matter who you are. The incident, and others like it, drove me to reconsider the ways that I was teaching students to respect the truth.

In the past, when I announced that it's vital to get facts correct through checking with multiple reliable sources, I sensed that students were automatically recording my words but not taking them to heart. So I have tried other strategies to explain the importance of verifying facts. Those include citing examples of badly fumbled facts from the worlds of politics and the news media, and dissecting the cognitive pitfalls that lead us to get facts wrong or lure us into thinking that inaccuracy is an acceptable practice. I have found, however, that the single best teaching tool is for a professor to expose his own blunders.

My general argument to students is that if you make a mistake about an obvious fact -- that is, one not subject to controversy -- someone, somewhere and somehow, will out you. I provide major and minor examples. Arnold Schwarzenegger, at the 2000 Republican National Convention, recounted how he decided that he would embrace the philosophy of the Grand Old Party after he saw the presidential candidates Richard Nixon and Hubert Humphrey debate in 1968. Problem: Nixon and Humphrey never debated in 1968.

Then there's Rudolph Giuliani in the days after September 11, 2001, brandishing a copy of John Lukacs's Five Days in London: May 1940 and claiming that its description of World War II Londoners holding up under the blitz gave him strength in the trying time after the attack on America. Problem: As the author of the book himself pointed out in an essay in The Chronicle Review ("A Final Chapter on Churchill," October 24, 2003), "there is not one word about the blitz in Five Days."

Although I devote substantial class time to talking about lies, or deliberate misinformation, I pay particular attention to errors like Schwarzenegger's and Giuliani's -- and mine about Edison -- cases in which the communicator probably did not intend to get anything wrong. I have an ideological agenda behind such instruction.

It is no great insight to say that today's youth are cynical. I do not know whether they are more cynical than any previous generation in history -- men and women who reached maturity at the end of the so-called Great War must be rivals for that position -- but my students do have a general perception that they are being lied to by those in authority, perhaps including their professors. Certainly the popular culture they ingest frequently sends the message that government, business, academe, and almost all institutions are engaged in innumerable conspiracies to cover up the truth.

In fact, Americans are lied to often. But democracies perish when faith and trust in the institutions of a civil society -- like government and the press -- collapse. So I want to make a case to my students that many of the misstatements they see are the result not of evil cabals but rather of plain boneheadedness.

My undergraduates seem to get excited about participating in a Sherlockian quest for error. Taking an example from blogs, which are responsible for publicizing a number of goofs committed or repeated by the mainstream media, I have students scour certain op-ed essays from newspapers and do some fact checking. But here's the twist: In most of the cases, I wrote the op-eds. I think when the students see my eagerness to hear about my own errors, they learn a valuable lesson: We all need to ponder why we make mistakes. And, of course, trying to prove their professor wrong is an added attraction.

Once the students turn in their results, I offer them a typology of the kinds of errors that I find myself making -- and usually catching, I hope, before publication. (For graduate students, recommended reading on this subject is David Hackett Fischer's Historians' Fallacies.)

In my case, the sins that lead to error are all too glaring, foremost among them laziness. Thanks to the familiar fallacy, I repeat without checking "facts" that I have cited numerous times and assumed must be true because of repetition (my own and that of others), and about which no one has ever challenged me. Edison's disk is a case in point: At some point in the past, when creating my lecture notes and slides, I made the error and then repeated it often enough, with no one correcting me, that it became an assumed verity. You must review claims of fact, even those that you have been repeating for a long time.

I also suffer from the fitting fallacy, an error committed because it seems to make complete sense -- that is, to fit into a set of other facts. I've written a number of essays, and recently a book chapter, on the Tiananmen Square protests and crackdown in China. As a visual historian, I focused on pictures of the event, including the famous one of the lone man standing in front of the oncoming tank. I know that, contrary to popular misconception, the man did not confront the tank in the square, but blocks away. But when interviewed by a New York Times reporter on the subject of famous news icons, I referred to "the man standing in front of the tank in Tiananmen Square." I made the same error that I had detected in others because it just seemed to fit.

I'm also dogged by the transpositional fallacy, an error that occurs when I inadvertently modify a fact and make it incorrect. I study images of war and the military. I know, as a piece of trivia, that Gen. George S. Patton owned pearl-handled guns. In an essay about today's media coverage of Iraq, I wrote that Patton would have pulled "his pearl-handed revolvers" on reporters. Seeing the sentence in print, I had to reconsider: Patton, I recalled, possessed pearl-handled .45 automatics. Had I made an error? It turns out that the general had owned pearl-handled revolvers as well, but I should have checked before submitting the essay.

Such are but a few of the reasons I make errors of fact, not regularly but often enough to provoke eternal vigilance. What I hope my students get out of analyzing their professor's foibles is that everyone -- they, I, the authors of textbooks, the president, Nobel Prize winners, and so on -- makes mistakes. The crucial questions are why the mistakes are made, and what is to be done about them. Our duty as teachers is not to produce students who will always get their facts right, but to foster young thinkers who appreciate that facts are indeed worth getting right, and who then take the most important step of candid self-analysis when they get them wrong.

Which is what I did when my student notified me of my error about Edison's phonograph: I sent the whole class an e-mail message admitting my mistake, congratulating their astute classmate, and wishing them a good summer. Not a few wrote back telling me that was the first time they had ever had a teacher admit that he was wrong about anything.

I hope it's not the last.

David D. Perlmutter is a senior fellow at Louisiana State University's Reilly Center for Media & Public Affairs and an associate professor of mass communication on the Baton Rouge campus.