College physics: Labs vs. Recitations?

[Pengwuino]

Have there been any studies done as to which is more effective as supplements to teaching introductory physics courses, labs or recitations? I've been having discussions with a fellow grad student who has never taught a intro physics lab about their effectiveness and also with a professor who seems to think they're usefulness is minimal at best. So what say the physics departments of the world?

 

[cristo]

For those of us not familiar with your terminology: What's the difference between the two? It seems to me that a lab is a practical, experimental class and a recitation (if I understand what you mean by that word) is a theory class.

 

[jtbell]

In US terminology, a "lab" is a hands-on exercise with equipment, e.g. measuring the period of a pendulum as a function of length and using it to verify that it's proportional to the square root of the length, calculate g, etc.

A "recitation" can be a question-and-answer sesssion with students, or going over homework exercises, etc. In large universities these are distinct from "lectures" which are a presentation of new material, often with demonstrations. Professors deliver lectures, whereas graduate students often handle recitations.

At small schools like mine, that don't have graduate teaching assistants, lecture classes include the "recitation" functions.

 

[Andy Resnick]

Our intro classes follow the standard model: each week has 2 lectures, 2 recitations, and 1 lab (5 credit hour class). There has been a trend toward "studio" type classes which combine lecture and lab:

http://bama.ua.edu/~stjones/studio/

This approach fits in with the 'peer instruction' model of teaching

http://www.physics.umd.edu/perg/role/PIProbs/

Which claims that students "learn better" when they teach themselves.

IMO, the specific method matters less than the ability of the instructor. Put a mumbling, sadistic, disinterested teacher in *any* environment, and the students will perform poorly.

So, some people are gung-ho for studio classes and peer instruction, others prefer the traditional format. I try and blend both- using in-class discussion combined with explicit worked examples (and an open-door policy) seems to be working.

Of course, in order to reach a conclusion over which is better, there has to be an *assessment*. Again, IMO, there isn't a readily available assessment yet that measures student learning, so it's difficult to really compare the two approaches.

 

[Pengwuino]

I like the idea of college students having to actually learn a scientific law through the use of a lab instead of being just told to verify it the way we tell them to. Our university doesn't have recitation sessions but our intro to physics courses are considered high-risk to our university. It seems like we have a lot of problems with students who struggle with algebra too far into the semester and can't really DO problems. I want to try to get our department to let us do an experimental recitation session, completely voluntary, and see if students attending them perform better than students who choose not to attend. It feels like the labs are just "come in, sit down, follow the lab manual and write down stuff in the lab manual". It doesn't feel like this is really teaching them anything.

 

[Pengwuino]

For those of us not familiar with your terminology: What's the difference between the two? It seems to me that a lab is a practical, experimental class and a recitation (if I understand what you mean by that word) is a theory class.

Our labs are yes, hands on work verifying concepts in lecture. I've never had a recitation course, but my understanding is it is as jtbell said: a session run by a grad student that goes over problem solving and question/answer sessions.

 

[Klockan3]

I think that it depends a lot on the individuals. To some students labs are very important while for others they are all but worthless depending on how good intuition they got and how interested they are in experimental physics.

 

[wild999711]

1st year labs are boring but are useful for building intuition for subjects of physics other than mechanics. Recitations on the other hand were ... mostly used by people hoping to get help on the problem sheets. Demonstrations done in class were better than both though.

 

[Andy Resnick]

For those of us not familiar with your terminology: What's the difference between the two? It seems to me that a lab is a practical, experimental class and a recitation (if I understand what you mean by that word) is a theory class.

Our labs are yes, hands on work verifying concepts in lecture. I've never had a recitation course, but my understanding is it is as jtbell said: a session run by a grad student that goes over problem solving and question/answer sessions.

Oops- sorry.

In my experience (both as student and teacher), recitation sessions consist of small groups of students (here, it's half the class; there, it was about 1/4 of the class) that is devoted to solving specific problems- homework, practice test, or other. For my class, I teach one and another prof the other (each section meets 2x per week).

Labs are basically the equivalent: small groups of students work together to solve specific problems with some sort of adult supervision on hand.

So I guess recitation sections are the theory equivalent of lab sections.

 

[Angry Citizen]

If y'all are interested in a student's perspective...

I find labs interesting, but they don't have much educational value. It was like a previous poster mentioned: I walk into the lab, I follow the instructions to the letter, I fill in the data tables -- and then I read the textbook to find out what all the junk meant. I understand that physics splits into theoretical and experimental physics, and the intro physics classes are supposed to give you a taste of that dichotomous yet interrelated relationship, but frankly, I don't believe it's practical to introduce the experimental side so early.

Intro physics courses are supposed to develop physical intuition for problem-solving skills, at least as far as I'm aware. Physics labs do little for me. What seems to be my main source of struggle in the class is the ability to adapt to new circumstances (for instance, in projectile motion exercises, you're typically given a list of knowns with one or possibly two unknowns; when asked to find three unknowns, the problems often take me over an hour, if I can do them at all). I feel that recitation would be far more conducive towards stimulating intuition, at least in my own case.

Lectures should be about introducing concepts and linking these concepts to foundational concepts. Recitations can then be used to solidify these concepts in the student's minds. Just my opinion.

 

[Andy Resnick]

If y'all are interested in a student's perspective...

I find labs interesting, but they don't have much educational value.

I predict that there are going to be a lot of labs incorporating blocks of graphite, tape, and voltmeters shortly.

 

[Phyisab****]

Freshmen level labs are essentially an exercise in following directions, in my experience. Recitations are good, if you force students to come prepared for example by having a quiz at the end of the recitation. This way you can work out gaps in your knowledge, and not just listen to a foreign grad student mumble about stuff you don't understand.

Honestly though, I am very glad I'm not in the position of trying to teach a general audience anything about physics. Especially when their goal is probably to pass the course while learning as little about physics as possible.

 

[Andy Resnick]

Freshmen level labs are essentially an exercise in following directions, in my experience. Recitations are good, if you force students to come prepared for example by having a quiz at the end of the recitation. This way you can work out gaps in your knowledge, and not just listen to a foreign grad student mumble about stuff you don't understand.

I don't think that's entirely fair- freshman level recitations are also an exercise in following directions: (1) draw a picture. (2) write down the coordinates. (3) list your knowns and unknowns... you get the idea.

 

[jhae2.718]

I've never liked labs, and have always thought they were pointless. I'm guessing the idea is to demonstrate theoretical concepts, but they've never seemed to accomplish that; as it's been said they are more of an exercise in reading comprehension.

Not to mention for freshman level labs, the equipment in my experience is mostly junk; our lab computers still run Windows 98, and it takes about 15 minutes to export data into Excel for analysis... (It probably also doesn't help that my labs/recitations are late at night.)

I enjoy recitations much more; in the class I'm taking it's basically an hour period with discussion of problems and a quiz; they're easy, but I enjoy them because I'm the physics/engineering nerd-type who can sit around and talk about physics all day...

 

[DR13]

The amount that I like labs (in college and in high school) varies greatly from teacher to teacher. The teachers that assign labs that are just following directions for 2 hrs seem pointless. They end up teaching nothing new and the students are uninterested. Also, and this is especially true in high school, the labs are poorly set up. The problem is that there is not enough money for good equipment so there is extremely high percent error. However, I really enjoy the open ended labs where students much use concepts that they know to complete a task. No directions. Just an objective. This makes students utilize concepts as opposed to just memorizing equations and processes. It also improves problem solving skills while keeping students interested.

 

[Pengwuino]

The amount that I like labs (in college and in high school) varies greatly from teacher to teacher. The teachers that assign labs that are just following directions for 2 hrs seem pointless. They end up teaching nothing new and the students are uninterested. Also, and this is especially true in high school, the labs are poorly set up. The problem is that there is not enough money for good equipment so there is extremely high percent error. However, I really enjoy the open ended labs where students much use concepts that they know to complete a task. No directions. Just an objective. This makes students utilize concepts as opposed to just memorizing equations and processes. It also improves problem solving skills while keeping students interested.

What do you define as "extremely high percent error"? And how does that really matter? You can probably use a ruler and protractor creatively and do pretty well with most things people learn in intro physics labs. Equipment is sometimes a hindrance.

 

[DR13]

What do you define as "extremely high percent error"? And how does that really matter? You can probably use a ruler and protractor creatively and do pretty well with most things people learn in intro physics labs. Equipment is sometimes a hindrance.

I have had errors over 100% (mainly in chemistry). We had to use a calorimeter but did not have a good cover (teacher gave us a piece of cardboard to put over a cup and the cardboard did not even cover the cup) and the results were completely off. Though it seems that percent error shouldn't matter it is very discouraging to students when they do everything right and regularly get high errors. But that isn't really the main problem. The main issue is that the fully directed labs bore students and do not really help them learn because they look at the labs as an annoyance as opposed to an opportunity to learn.

 

[Andy Resnick]

The main issue is that the fully directed labs bore students and do not really help them learn because [...]

One of the AAPT New Faculty sessions was in regards to labs, and was led by a couple of profs who had written a 'student self-directed' lab manual. Their aim was to address exactly what you bring up- and their claim was that, by letting the students self-direct, the learning experience is improved.

I'm not convinced: to make their point, we were broken into teams and given a pile of stuff (batteries, LEDs, a comb, some wires, and some plastic lenses). We were given a "topic of investigation" (in this case, refraction), and some questions to answer. Seems reasonable.

Well. I took the guys at their word- they wanted us to self-direct. So, my lab partner and I played. Turns out you can generate quite a lot of cool optical effects with a comb, none of which has anything to do with refraction or lenses. Besides that, we had fun just playing with the LEDs.

When I brought this up in discussion (that self-directed students may not address the topic at hand), the profs admitted that they go through a lot of LEDs and batteries from students intentionally mis-wiring things... since they are told to 'do whatever they find interesting'.

Now, factor in safety issues: our labs routinely use high voltage supplies, open flames, etc. etc. We simply cannot allow students to 'play'.

Freshman and intro labs are really about developing *technique*- keeping a lab book, obtaining and analyzing data, introducing them to specific measurement methods and apparatuses (apparati?).

 

[DR13]

I admit that not all labs fit into the "Let students figure it out" strategy. But I will give you an example of one that easily could have been. In my senior year AP Physics C class we did an experiemt where we we given a "cannon" (it was a spring loaded device that fired a small wood ball). We were told to find out the angle that give maximum range (obviously, it was 45). So most of the groups in the class spent the hour and a half talking about life after finishing the lab in 20 minutes. The lab consisted following directions about what trials to do and where to record the data and it even gave you the equations to use to find the theoretical value to get percent error. Me and my labmate were bored and decided to give ourselves a challenge: to hit a target on the floor with the cannon ~1m above the ground on a desk. We would not use trial and error but rather derive an equation to hit the target. After some real work we ended up doing it and could hit a target placed anywhere in the range. What we did really taught me something. I learned how to derive my own equation as opposed to just memorizing a derivation given to me! It was exciting and interesting and I felt like I actually did something. Obviously, not all labs lend themselves to self-directed labs. But there are many labs that could be self-directed that are not.

 

[Moonbear]

Personally, I think all science courses should include a lab component, whether as a separate course or integrated into the lecture course. I did far more of my learning in the lab courses than in lectures. My students often tell me the same. Seeing something happen is much easier to understand than someone talking about it in abstract terms.

As for recitations, I think they have potential, but often fall short. When I was in college, they usually were nothing more than, "I didn't understand how to do homework problem number 12, can you explain it?" and then having a TA solve the problem for the class. That was generally a waste of time, especially if you were one of the 90% of the class who was able to solve that problem on your own. If the TAs were given more training on how to run a class, and used the time to ask the students more questions instead of the students asking and the TA answering, the recitation sections could be a very useful study opportunity.