Tuesday, October 07, 2008

Partial Credit Fraud

Many students, when faced with a test or homework question that they cannot answer, will attempt to get some credit for the answer using a palinesque approach of “I don’t want to answer that question (because I don't know the answer), but I will answer a different, perhaps even unrelated question, for which I do know the answer and maybe you will forget that I am not answering the actual question and give me some points.”

Speaking as someone who does a fair amount of grading, I know that it is in fact psychologically much easier to give zero points for a question left blank than it is to give a zero for an attempt at an answer. Even so, a totally wrong answer is a totally wrong answer.

I am happy to give partial credit for a partially correct answer, but I do not consider the presence of random markings in graphite or ink sufficient for partial credit.

A related phenomenon is when a speaker (e.g. a professor giving a department seminar; a student giving a talk or oral exam) feels that every question must have some answer, even if the answer if not known (to the speaker). It can be painful to say “I don’t know”, especially in some circumstances, but is giving a bad/random/wrong answer better than saying that you don’t know?

A better alternative to a flat-out "I don't know" might be“I don’t know, but..” and then talking about possible answers or ways to approach figuring out the answer. Or is that like asking for partial credit?

I can understand a student’s wish to write something and not leave an answer blank, on the off chance of getting some points, and I can understand a speaker's not wanting to seem stupid or lacking knowledge in front of an audience. These are facts of academic life. Even so, for some reason the 'partial credit' attempt bothers me when it permeates debates and interviews involving candidates for major political office.

23 comments:

Alex said...

My quarter just started a couple weeks ago, and I have 110 pre-meds in my lecture. I know exactly where you are coming from.

I love online homework systems for various pedagogical aspects, not to mention automated grading, but the complexity of the grading formula and the fact that some problems have hints while others don't gives them endless new avenues to grade-lawyering.

Anonymous said...

The question is do they write something *in the true belief* that they are answering the question, or do they make a conscious decision to write "something" in the hope of getting some marks from your generosity.

In my experience it's not so easy to distinguish between the two.

CookingWithSolvents said...

I find your comment about speakers VERY interesting because I've always been told that if you don't know the answer it is OK to say you don't know. However, one SHOULD be comfortable saying something hypothetical if your research has given you something to say about it. (a "feel" for the situation)

Many speakers I've seen encounter those "wow, I never thought of that, I don't know" questions have had a "well, in THIS situation we see X (usually some unpublished / not-in-the-talk result) so maybe it would go Z, but I don't know."
Perhaps my B.S. meter is calibrated differently or would that be OK in your view?

I can't recall a specific incident of "I don't know but I would do YY to find out", though I've almost certainly seen it. I'm not a fan of that in talks. Never administered an oral examination so I don't know how I would feel about a student doing it. I'll have to think about it.

Candid Engineer said...

A student looking for partial credit is entirely different than a speaker at seminar. Presumably, the speaker is an expert in his/her field, and the student is not. If the speaker doesn't know the answer, then the answer probably isn't known by anyone, end of story. Yes, some further insights/ details on how to answer the question are appropriate. But such a discussion is hardly looking for extra credit.

Regarding political debates, I am in favor of arming the moderator with a slingshot, for use when the candidates do not answer the question they are asked.

Ambitwistor said...

My high school teacher once told us about a student he'd had, who made up an entirely new exam and answered it in detail. The teacher even admitted that many of the questions on that exam were better than his own. He said it was a shame he had to fail him.

NewYorkPhDstudent said...

As a PhD student, I often hear other students from my lab answer a question they were not asked while ignoring the actual question. It is very frustrating, but I usually chalk it up to language barriers. (I am the only female American in a lab full of Asians.) However, my advisor, also Asian, doesn't seem to mind, and indeed thinks these people are very smart. Maybe this is a cultural difference, but I neglect to see how a failure to communicate is a positive in any scientific field.

On a related note, I could use some advice on how to deal with the people in my lab and my advisor. I am too entrenched in my research to leave. (I estimate I could finish in 8 months, so let's assume I can graduate in the next year and a half.) It is clear that my advisor is not going to change; he is poor at lab management, completing projects within the grants' deadlines, and most of his students do not know even half of what he thinks they do. In the meantime, I have basically become a grantwriter/proofreader/secretary, with little time for my own research and very little credit or appreciation for keeping the lab afloat. Now my advisor would like me to recruit more American students to his lab, which I do not feel comfortable doing, as I do not believe they would be happy nor would it serve their careers well. What is the best thing to do in this situation?

squawky said...

Regarding the "I don't know, but..." answers - that was always a piece of advice I gave to fellow grad students going up for orals. The idea was that the committee is pushing their knowledge to find out how the student will react when they don't know an answer - can they come up with a logical train of thought that is related to the question or do they fall apart?

But that's a lot different than a mid-semester exam.... where I'm much more inclined to be picky with long-winded 'I'm not sure what you wanted so here's everything I remember' answers. I'm so sick of writing 'Not relevant' and 'Does not answer the question asked' - tempted to get those put onto rubber stamps for next term. So tempting to add penalties for this kind of thing, too.

yolio said...

There are two kinds of questions that a seminar speaker can say "I don't know" to: Questions that they have reason to know the answer to and questions that they really should know the answer to. ditto for the politicos.

Few things are more impressive than a well delivered "I don't know" to a question in the former category. If a speaker can admit to their ignorance without a shred of shame, and give a good succinct follow-up, this conveys confidence and intelligence.

It is troubling when they bullshit their way through these questions. It is triply troubling when they bullshit their way through questions that they really should know the answer to. Ditto for the politicos.

AsstFemaleProf said...

The phenomena of speakers refusing to admit they don't know an answer is something that particularly resonated with me. Several of my female friends and I have had extensive discussions about this, and we have come to the conclusion that this is a very male trait.

In my field, presentations at conferences are viewed as mini-oral exams, in a sense. They can be very confrontational. I have given many talks, and have been faced with many questions that I either didn't know the answer to or that hadn't been explored yet (ie no one knows the answer to). In those situations, I usually simply state as much. Many of my male colleagues will invent an answer, and say it so emphatically, it sounds as though it came from a text book (there is no qualifier indicating that they are hypothesizing).

It is really frustrating because when I was a student, I had a hard time distinguishing from the real answers and the guesswork. Now that I know more, I just want to correct the speakers all of the time to protect the students.

Ψ*Ψ said...

Your first paragraph reminds me of the vice presidential debate last week. I wonder why...
I've seen a lot of grad students try to BS answers to the questions asked when they give seminars. They inevitably get torn to shreds...I'll just stick to admitting my ignorance.

Carrie K said...

But is it a "talking point"? Sometimes getting politicians off message is an excercise in futility.

As for a student, I suppose partial credit could be awarded for realizing that it was in fact a question.

Anonymous said...

As an MD, the first few times I said, "I don't know, but..." to a patient, I was scared that they'd think I was an idiot and never come back to me or call the state medical board to tell them I was incompatent. However, people seem fine with it, especially if I look up the answer or talk with some one who is an expert and get back with them.

I also was embarrassed when I had to look up a dosage or how to prescribe something and thought that that would undermine patient's confidence in me. In fact, it seems to have the opposite effect. Now, I say to people, "I don't know that, because I can't know everything, but..."

Unbalanced Reaction said...

I was grading exams during the VP debate. The parallels were striking.

Anonymous said...

I've been known to give negative points if I feel that the student is just wasting my time and not even trying to answer the question. You only need to do that once or twice; the students quickly learn to leave the question blank if they have no idea what the answer is. (But I do give generous partial credit if they do something as basic as give correct definitions for terms used in the question. Just not if they wander off on some completely unrelated topic.)

Twice said...

One former colleague of mine occasionally gives exams in this way: If a student leaves a question totally blank, they get 1 point for that question. The rationale being (a) if you don't know anything, don't waste her time and (b) knowing you have no idea about something is worth knowing.

Dr. Jekyll and Mrs. Hyde said...

Well, I'm sure tonight's debate made you feel Much Better about our future presidents' collective ability to answer the question that was asked!

Demerits all round, I have to say...

Anonymous said...

In the talk/speaker situation the correct response to a question you don't know the answer to is:

"That is an excellent question/suggestion. I'm definitely planning to look into it."

I wonder if that would be equally valid on a written exam? :)

Ms.PhD said...

Yeah, but she looked like an idiot with Katie Couric when she said she didn't know.

Experienced folks, including many professors I know, are taught to answer the question desired, not the question asked. At least, that's what my advisor tells all of us to do.

(I'm not very good at it.)

But I don't have any problem giving a zero for something that's just totally wrong.

The only thing I know for sure is, yes, a blank answer is an automatic zero.

But that brings to mind a funny grading system. I did have two teachers (one in high school, one professor in college) who SUBTRACTED points for bullshit.

In that case, a bullshit answer got less than zero; a blank answer a zero. Sort of like on the SAT (do they still do this?) where you're penalized for guessing.

I'm with you, I'd rather hear I don't know, if for no other reason than it wastes less of everyone's time.

And I take points off for bullshit.

Anonymous said...

To further your analogy, if anything I'm more likely to give credit when the student makes it clear that they know they're not answering the question. (I also give more partial credit if a student makes clear that an answer fails a sanity check, e.g. negative probabilities.) Far preferable to the every-other-politician approach of doing away with the preface yet still only repeating the talking point they have that's closest to the question, though unlikely to actually address it.

Arlenna said...

I'm teaching an organic chemistry course with 300 students, and we give partial credit. So, on one of the questions on the last exam that was about arrow-pushing in a simple organic reaction mechanism, about 90% of the students had no idea how to do the problem (this was a major issue in itself) and hadn't left themselves enough time to work through their logic process to answer it even partially correctly. So about 80% of them just drew arrows coming from and going to about every atom in the two molecules, in the hopes that some arrows would be correct enough to get them some points. Even though it was funny for us to grade that, all of those people got zeros, lol, for not even having the foggiest idea what you do with electron pairs and electrophiles even though we had been talking about it in classes and help sessions for about three weeks.

Anonymous said...

What you need to do in your tests/quizzes is to adopt a method sometimes used in multiple choice tests.

After each answer students have to indicate whether they are a) confident b) semi-confident or c) unsure of the accuracy of their answer. So if you get a poor answer with a) you get zero, but a poor answer with c) might gain some partial credit for some element of insight. Max marks only come with the right answer and a).

Tina said...

Making up answers, not answering the question that is asked... is this science, or is it politics? In my very limited teaching experience I have had no problem giving zero credit, but I am amazed at what students will try to get away with. But I really wanted to comment about seminar speakers who can't answer questions; I've never heard a very senior investigator admit to not knowing an answer, but I frequently hear younger scientists admit "I don't know" and either verbally work through to an answer, or say that it would be a good idea to look into that. I wonder... is the older investigator really that much more informed, or that much less willing to admit that they might not know something?

Anonymous said...

I flat-out state on exams that marks will be deducted for "incorrect information added to an otherwise correct answer" in an attempt to avoid fishing. I also don't give any credit for word salad answers; using the right words isn't enough - they have to be connected together in a coherent fashion to give a reasonable answer. I don't delve into the realm of negative marks though; the worst you can do on a question is zero.

And don't students realise that by randomly making up their own questions, they may happen to answer the questions on another version of the test? Making us think they're cheating? We had to deal with that not long ago and it was not a fun experience for anyone.