I got the last round of line edits on the book-in-progress Monday night after work, but I haven't had a chance to do more than leaf through the pages. This is mostly because I had lab reports to grade-- the second written report is due Sunday, and I needed to get comments back to the students before they start on the next report.
(Yes, I know, as a practical matter, I could've waited until Saturday for that, but I hope for better.)
Grading labs is just about my least favorite part of the job (narrowly edging out committee meetings), and since this is turning into a blog primarily about curricular issues in physics, I thought I'd throw this one out to my readers:
Are you in favor of having students write full formal lab reports? How many should they have to write?
I'm pretty ambivalent about this, mostly because I never had to write formal lab reports as an undergrad.
This may have changed by the time I graduated-- they dramatically changed the way the sophomore E&M class worked about two years after I took it-- but when I was an undergrad, labs were graded on a binary scale. You came in, did the experiment, printed out the data and answered a few questions, and then handed the resulting packet of stuff to the TA. The TA marked it down as completed or not, and that was it.
This was a whole lot easier on the faculty, but it's not clear whether it's better or worse on the student side. Writing formal lab reports does involve some drudgery, to be sure, but it also gives students practice at writing in a technical manner. I'm not completely sold on the idea-- the formal lab report structure is almost as artificial as the five-paragraph essay-- but it does at least give students some practice in writing about science.
These reports are the bane of my existence as a faculty member, though, because they take so long to grade. It's not so much the assigning of numerical grades-- I can do that very quickly-- it's the writing of constructive comments. There's really no point in having students write stuff if you're not going to give them detailed feedback, and line editing their writing takes forever.
Part of the problem is that we're trying to do several things at once. We want them to understand the physics involved enough to talk about it sensibly, we want them to write in a reasonably competent manner, and we want them to do data analysis and error propagation. Trying to do all of those at once is overwhelming for some students, and trying to grade them on all three at once is overwhelming for a faculty member. If a report contains confused physics, no paragraph breaks, and no error analysis, which of those is the most important to address? There's a kind of error fatigue that sets in after a while, and it's really hard not to let stuff slip on page five after marking up every single paragraph of the first four pages.
I don't know a better way to do things, though. So I have the students doing three lab reports per term, which gives me just about enough time to finish marking up one lab before the next one is due. In the modern physics class, I have them do oral reports for the other four labs, which are not without their problems, but at least they're over quickly.
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I once taught a class for Ph.D. students. They were smart kids with good grades from undergrad. But when I had them write a paper, they were hopeless. That's when I vowed to make my undergrads write about science, so that by the time they got to grad school this wouldn't be completely foreign to them.
Yeah, yeah, the lab report has its flaws as a medium, but you have to start somewhere. If I had a better opportunity to include writing in the curriculum, I'd grab it in an instant.
With lab reports, I now have an appreciation for the English department.
Do you run them through TurnItIn.com? You might be surprised to find a few discussion sessions or the occasional introduction there.
We have our Intro to Astronomy lab students write 9 "lab reports" that usually run 2-3 pages. The format is pretty structured and the labs are relatively simple, so it seems like it would be fine until you realize that the kids taking the class are Theater/Economics/Event Planning majors, and virtually none of them have taken physics (or even Astronomy, which is not a prerequisite). It's a pretty bad setup. But of course, being a TA, the format for the class is handed down from on high, and you have to pretend not to agree with the students when they start grumbling about the class being way too much work for only one credit. It makes giving anything but an A an exercise in sadism.
I am currently TAing a sophomore lab course and know all to well that excruciating experience of marking lab reports. Our set up requires most of the completed labs to do proper data analysis and make appropriate graphs. They also must show their reasoning (e.g - linearized this equation by plotting this VS that and used the slope to find the constant of interest in this manner). Then they write a conclusion and discuss why their results were off, etc... etc... These reports are usually 8-10 pages hand written including graphs and tables. Then once or twice a term they have formal reports where they dress up the work they do for the other reports with a proper introduction, an indepth discussion and conclusion, with proper references.
Although its terrible to mark these generally, (especially the bad ones!) it is certainly important for the students. And these labs are the first time these students don't have every step laid out for them. It involves lots of thinking.
I think the answer to your first question depends on the lab. If it is a lab for non-science majors then lab reports are not too important. Labs for majors - they need to learn how to write, right?
I typically have them turn in ungraded rough draft lab reports each week, and have 2 formal lab reports for the semester.
You seem to have discovered the problem. There are several things we as faculty want to get out of a lab - conceptual understanding, understanding science and experiments, measurement and uncertainty, and finally improving their writing and communication (which I think is very important). In a lab, you can pick 1 maybe two of these things to work on - but not all.
For the intro to the major courses that I have taken and TA'ed, the lab reports always focused on answering specific questions. If you can think up good questions that gauge the students' understanding of the lab in a paragraph or two, you really can cut down on the amount of verbiage you need to read. Having designed my own labs, I will say that this is a hard thing to get right.
A friend of mine, who studied chemistry before becoming a computer programmer, got high marks at his first employer for his writing. He said he just wrote everything in the same style as chemistry lab reports. Apparently these exercises can be more useful than one would think.
I was a chem major 30 years ago. Every experiment (g-chem, o-chem, p-chem) involved a lab report. It was good writing experience for me, and I'm grateful almost every day for learning to explain why I was doing what I was doing. (That was the o-chem prof. If you couldn't explain what you were doing, he knew that either the lab was wrong for the lecture or the lecture was inadequate. He fixed it every time. What a wonderful instructor he was.)
The only reason I switched to Comp Sci was because my assigned lab partner in Physics 1 was trying to kill me. We did the classic pendulum experiment with the electrified pendulum and the electrostatic paper (to see the dots mapping the pendulum swing) and he dropped the electrified pendulum onto my back while I was changing the paper. We did the classic inclined plane experiments and the weight was consistently dropped on my toes. This held true for pretty much every lab. My lab reports generally read "I didn't learn anything in this lab that I didn't already know because my lab partner is trying to kill me. Please do not assign lab partners." That professor was Teh Loser because he never acted on any information gleaned from lab reports.
Since you can't get a chem degree without at least a few semesters of physics, I decided Comp Sci (and eventually tech writing) were a safer way for me to go.
Lab reports should be short-ish and to the point.
Like this one.
When I was an undergrad, we were required to write a formal lab report every week for the physics and chemistry labs in freshman and sophomore year. If we didn't do the error propagation properly, we were automatically given a failing grade for the particular experiment. If we didn't write an adequate discussion, we were also automatically given a failing grade for the particular experiment.
The only reason they did this was mainly for "weeding out" purpose to throw out as many premeds, engineering, and science majors as possible. This was basically the "waterboarding torture test" they deliberately inflicted on students, to see who would sink or swim. In the end, almost half of the students failed the freshman physics and chemistry classes.
Full lab reports (intro, M&M, results, discussion) are daunting to students and mind-numbing drudgery to the grader. You can barely get the first one back to them before they have to turn in the next one, and you have given them an overwhelming list of errors they have to avoid in future papers, that they can't remember them all and wind up making the same mistakes over and over (which, of course, forces you to write the same comments over and over). Even if you set up a mail-merge file to produce the comments, and a spreadsheet to log who required which one, the task eats up your entire weekend.
I like to assign small, teachable chunks. Here are some examples of my assignments (given only one or two at a time):
*make an accurately plotted, correctly labeled graph, and write a single sentence telling the reader what it's supposed to show.
*summarize the experiment in one sentence.
*explain the method in one paragraph. (No cookbooks!) This is a good quiz question for the beginning of lab.
*write a 200 word abstract.
When you break the process into small tasks, it is easier to get the students to learn how to do each one.
Laboratory reports are generally intended as a 'mini' research paper, which is meant to ease students into the process of formal scientific writing (in the style of a journal article).
Unfortunately though, most undergraduates have no exposure to the type of primary literature that they are supposed to me imitating (as opposed to popular science writing).
In my undergraduate days, when I first began working in a research lab (and therefore first started reading research journals) -- I recall that lab reports suddenly made sense to me for the first time.
So, I would say that full lab reports are useful, but only after students have been forced to read and review several formal research papers (this is rare).