Lab Grading Macros

Rubber stamps and an index? Why spell out the stock notes when they can be part of the class FAQ and incorporated by reference?

I found out a long time ago that a minor investment in rubber stamps can save a fortune in writers' cramp.

This is a Physics class, not a hook-up. I don't care what you "felt" about the data. This is not a poetry, music, or dance class. The data are the data. Do they or don't they statistically support the hypothesis or the null hypothesis?

When you say "The variation of our error was within reasonable uncertainty of human error" I have no clue what you're saying.

The two I always find myself using:

• "Use proper units."
• "You did the experiment already, so use past tense. You aren't writing a manual."

Do not talk about the educational purpose of the lab. Pretend that you did this experiment on your own, because you wanted to learn something, and not because I made you do it for class.

I hope you don't take off for that (unless you've already told them so, or given them a warning). For a lot of students, that IS the sole purpose of the experiment, and they wouldn't care for any other reason. So unless informed they're supposed to be pretending, it's a quite honest answer.

So are lab reports all electronic now? I always used a red pen and wrote illegible comments.

Human Error! Oh, how I hated that one! It was the source of all difficulty in every lab write up, no matter how often I pointed out that what it means is "we screwed up, we know we screwed up, and we didn't fix it."

"Not only were you able to [verb] the [noun], you did [verb] the [noun]. Say that directly."

A nitpick: for that one the student version is arguably better. "was able to..." has an established meaning of "tried to do ... and succeeded". That's a different idea from simply "did ...", which doesn't carry any connotation of trying to do it without knowing whether you'd succeed or not. You could certainly argue that "succeeded in ..." or "managed to ..." would be better (I'd prefer that), but your suggestion is not an alternative since it changes the meaning.

My favorite peeve: don't use passive form. Acknowledge that you're part of the picture. Use "we ran the simulator on two data sets", not "the simulator was run on two data sets" (or, horror, "Two data sets were applied to the simulator"). You did it. Show that. I know many papers use passive form, but that's no excuse. It doesn't make you sound intellectual; it just makes the text harder to read, and makes you sound weasely and unwilling to take responsibility.

Ok, there's just simply nothing wrong with the "were able to" construct at all. Everyone knows what it means.

The rest, I agree with!

"Were able to" is definitely bad style, not to mention that it's annoying to read it multiple times in 30 different papers. It's just less direct, so don't use it.

The argument that it means "tried and succeeded," is not the context where I usually see it. "We were able to measure the length of the cart"describes a pretty straightforward procedure, even for students in intro labs.

Exactly. I think I will go a step further than creating a macro, I will just write this URL on their paper - http://tinyurl.com/yourlabmistake (which points to this page).

Another comment: the "I hope to find" thingy. I also see this one (and all the others) on lab reports and there is something very middle schoolish about this. Then I realized that this is what middle schoolers say for their science fair projects. I wonder where they get this from.

At one point, I really tried to help students create better lab reports. One thing I did was to have them submit all or part of their report electronically (like in WebAssign) and then randomly and anonymously give them other students's lab reports to evaluate. I think this had several positive aspects. They would write a little more carefully knowing that other students would see it (surprisingly) and they would get a sense of some of the mistakes other students would make. Unfortunately, there was still some stuff that was wrong that they would think is fine.

In the end, I realized that trying to help them with lab reports AND experimental design AND measurement and uncertainty AND learning the physics concepts was too much to accomplish in a lab.

"I am returning these otherwise good sheets of printer paper to you. Somebody has printed gibberish on them and put your name at the top." Based on a famous (possibly urban legend) comment supposedly made by a professor in the 1960s.

Also a comment on "were able to". If the student in question managed to do some part of the lab, but some other part of the lab didn't work for some reason, "were able to" is the correct description of the part they successfully did. This scenario is especially likely to come up in an astronomy class with labs that involve looking at objects through a telescope; e.g., they could see Saturn and sketch the rings, but Jupiter was hidden behind clouds, preventing them from sketching the Galilean satellites.

"We observed Saturn. We were unable to observe Jupiter."

Don't need the unnecessary words in the first one.

I'm in total agreement with #5. I don't see what's gained from pretending that they are doing Real Science instead of walking through a cookbook recipe for a lab. Is the real objection that quoting "educational purpose" is just something that's too easy to take from a lab book without even having to paraphrase?

In a similar vein, when you're in a 3 hour lab class, there often isn't going to be time to go back and fix an entire lab if you've made some kind of mistake. The real problem with "human error" isn't that they didn't go back and fix it but that it's too damn vague. What kind of error are we talking about? What did you guys do wrong? An honest assessment of this kind of thing probably has more pedagogical worth than doing the lab "correctly" on average.

The physics education people that I TA'd for one semester had a style of lab that was much more open ended. They'd give their students some goals, and then let them design experiments to accomplish those goals. I'm very receptive to this tactic; the only things I remember from undergrad labs are learning that I hated aligning lasers and the one pair production lab we did in quantum where we had to figure out how to use the electronics we were given to do coincident detection. I think there's a lot to recommend about this approach in terms of getting people thinking and giving them a big picture view of things. They'll not have some of the same facts, but I bet their ability to pick up those facts later when it becomes necessary is somewhat better than comparable students in a more conventional class.

There is an add-on to Turnitin, called Grademark, that lets you do exactly this thing (record comments and reproduce them with a single keystroke on a student papers. When we demonstrate it in workshops, the faculty act as if someone just gave them a raise. Unfortunately, It's not free.

Ah, good old "human error"! It's the "Goddidit" of lab reports. You can explain away any discrepancy with it.

I'm with Janne on the passive form. I used to get this all the time in the college lab I taught, and I hated "a graph was created."
I'm also with all the "human error" haters. My students use it for things like reaction time, and I have a real struggle to get them to write "reaction time" instead of "human error!"
Do you mind if I copy and modify these to hand to my students? I was thinking of just printing them on teh back side of my rubric and circling the numbers of the ones that apply. It's like the Turnitin Grademark thing but FREE.

Janne:A nitpick: for that one the student version is arguably better. "was able to..." has an established meaning of "tried to do ... and succeeded". That's a different idea from simply "did ...", which doesn't carry any connotation of trying to do it without knowing whether you'd succeed or not. You could certainly argue that "succeeded in ..." or "managed to ..." would be better (I'd prefer that), but your suggestion is not an alternative since it changes the meaning.

The goal here is to teach students to omit needless words. Far too many students have the idea that it "sounds scientific" to write lengthy sentences in the passive voice, with lots of extra qualifiers. That's just bad writing, not "scientific" writing.

And also, as someone whose grad-school research was mostly published in PRL, I had it drilled into my head that "were able to verb" requires tne more characters than "verbed", and when you're trying to fit significant research into four pages, you need that space.

bcooper: I'm in total agreement with #5. I don't see what's gained from pretending that they are doing Real Science instead of walking through a cookbook recipe for a lab. Is the real objection that quoting "educational purpose" is just something that's too easy to take from a lab book without even having to paraphrase?

The point of that requirement (which I do state in the how-to-write-a-lab-report guidelines) is to force them to think about what they did in the lab, rather than just writing "The purpose of this lab was to demonstrate the important concept of [Lab Title]." One of the many goals of lab classes in general is to teach something about writing in a technical context, and unless you're doing lab development in a physics education research program, the important thing is what you measured and how you measured it, not how it reinforced concepts that you learned elsewhere.

Technical reports are written in a very particular style, and the best way to learn to write in that style is to practice writing in that style. Which means pretending that you're writing up an actual experiment, and not just copying a cookbook recipe from the lab handout.

Which brings me to Rhett: In the end, I realized that trying to help them with lab reports AND experimental design AND measurement and uncertainty AND learning the physics concepts was too much to accomplish in a lab.

I agree with you, but this is a minority opinion. So I'm stuck trying to do all those things as best I can.

Did I see appropriate sig. figs mentioned? Proper match between the value and its uncertainty? (e.g. 3.672 +/- 0.5823 rather than 3.7 +/- 0.6) Maybe that has been resolved by the time they get to your class.

On the last item in your list, I'd be tempted to write something more to the point, such as "this sounds rather like it was copied from a report for the version of the lab we did in 200x". Or does it create problems at your college if you more clearly imply the existence of an obvious instance of plagiarism?

Do you check the internal authoring history info in Word files, or do they send you a pdf?

My favorite peeve: don't use passive form

When I was doing reports we got docked marks for not using the passive form. It was something they hammered us on as much as omitting units or graph labels

@ #20:
Our chemists insist on it. Physicists complain about it. That is just a small sample at our CC and in my other experiences (including journal articles).

@ #14:
That assumes the reason for the lab report is to report on the lab experiment. It isn't. It is practice in technical writing, including reports that go up the chain of command (to sell your idea) or across to another part of enterprise (to develop it) in business as well as in academic research.

As annoying as these things are to you, at least you have some authority to tell students they are wrong. When I was in college, the bio department worked by having group students turn in group lab reports. I had one person in a lab group who insisted on using "utilized" because she thought it sounder smarter. There were plenty of other problems too. But, when I told my various groups that they were completely wrong, they refused to believe me. Sometimes I was lucky and we would have a chance for a teacher to look at our rough draft and back me up, but plenty of times I got a mediocre grade because the other 3 people in my group would not listen to me. That makes all these things 10 times more annoying. Fortunately, my chemistry and engineering labs were either independent or just partners, which worked out better.

Oh, lab... I always loved the "source of error" portion of the lab, it always gave me a chance to complain about everything that's wrong with first-year lab assignments. Maybe they're just saying "human error" to be nice:

"The primary source of error in this experiment was contamination. Because they have been used for Freshman lab assignments since 1987, all the test-tubes in our set have a thick yellowish residue caked to the inside. We were unable to obtain replacements."

"The primary source of error in this experiment was interference from other experiments. Given the small amplitude of the sounds involved, other lab groups' conversations caused much more interference than the sounds being studied. Also, due to laboratory space constraints, other groups' emitters were often closer to our receiver than ours were. No useful data were produced. This is especially striking in data set 4, from which we calculate that our receiver was located in the linguistics building."

I had so many TAs that decided to mark me down for treating "data" as a plural...

On one memorable occasion, an argument with a biology TA that didn't want me referring to a quantity measured in grams as "mass" rather than "weight." Being a snarky Freshman at the time, I gave it back with the units converted to milli-Newtons. Ah, the sins of a misspent youth...