scientific method labs
David L. Robinson
dlrobi02 at HOMER.LOUISVILLE.EDU
Tue Aug 12 17:37:35 EST 1997
I occasionally do "The Black Box" lab as an intro to scientific
methodology. I use the little black canisters that Kodak film comes in
(you can get lots from camera stores) and put 1 or 2 objects like nuts,
bolts, paper clips, chocolate chips, washers, etc. Then give one
container to each student and tell them that no matter what, they are not
allowed to open the container to see whats inside their canister.
Their goal is to figure out what is in the container. You have empty
containers around (as controls), as well as duplicates of everything that
could be in them. After rolling the cannisters, listening to what they
sound like when shaken, weighing them, and boiling them (the chocolate
melts while the metal objects don't) they guess the right contents about
70% of the time.
A few years ago someone in this newsgroup suggested that at the end of
the experiment the teacher not tell the students whether they are correct
in their guess.....because that is what "real" science is like: one never
does find the real answer.
On 7 Aug 1997, Anne Heise wrote:
> The first lab for the soph. level general botany course I teach is often
> on the first day of class, so I like having a lab that students don't need
> to have prepared much for. For the past sev. years it's been a scientific
> method lab. The one I've tried a few times is to have students put a leaf
> in some boiling water, hopefully observe the bubbles escaping from the
> leaf, and ask them to test as many hypotheses as they can about that
> observation (e.g. it's the water, not the heat of the water, that causes
> the bubbles to escape). But this hasn't been as reliable as I've hoped.
> A few days ago I thought of asking students instead to investigate the
> browning that occurs when you cut open an apple. Is it exposure to air,
> is it the damage due to cutting, what about lemon juice prevents it from
> occuring (e.g., is it the wetness of the lemon juice, its pH, or what?)
> Not having tried this w/ students, I naturally think this problem could
> work really well! It doesn't require much knowledge of plants, it should
> be a familiar phenomenon to most, it won't cost a lot, etc. I'm tossing
> this little embryonic idea out to the group to see what other ideas people
> have about scientific method labs, and whether you have any particular
> comments about messing around w/ apples.
> At the end of such a lab I have students do a very quick "poster session".
> I supply overheads and markers s and have them present one of their
> experiments to the rest of the class. They don't love this, but I think
> it helps make the lab seem a little more important.
> Another thing we do, I guess in the second lab, is critique a lab write-up
> done by a student a few years ago. This write-up has some good things and
> some that aren't terrific, and my hope is that if students take the time
> to figure out for themselves what is good and bad about someone else'e
> write-up, they'll start producing good ones of their own a little sooner.
> What else do you all do to help students write up labs well?
> Anne Heise
> Washtenaw Community College
> Ann Arbor MI
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