Black Box - a summary

Cris Woolston c.j.woolston at
Thu Jul 27 03:49:16 EST 1995

Many thanks to you all for putting me straight on the 'black box'exercise -
in particular Guy Farish, Steven Wolf and Jon Monroe.

I had missed the fact that you can give students a list of possible objects
(or give them a duplicate set) so that they can use their powers of
deduction to identify which is in the box. This makes the exercise much
more credible to me, I was really having difficulty with the students
effectively having an infinite choice of possble items.
Another feature which makes the exercise work is giving the students access
to a reasonably full range of laboratory equipment (balances, waterbaths
etc). I had assumed that this exercise was done in a 'tutorial' type of
environment where this equipment would not be available.

I had also overestimated the size of the boxes - Steven's suggestion of
using a 35mm film canister is a good (and cheap) one.

I particularly liked the idea of putting a sweet (candy for you US people)
into one of the boxes so that there is a difference in behaviour at
different temperatures (and also that the treatment is not reversible)! In
fact I've been trying to think of a reverse example - possibly a small
amount of water sealed into a thin plastic bag - which would show
reversible behaviour at ambient and low (-20) temperatures.

This final comment from Guy:

>The idea is that they learn you can infer what an object
>is by indirect means and comparing it to something you already know
>about.  [...] When they say "My box contains a
>marble", you ask them how they know.  Ask what other possible items it
>might be, and what evidence they have that supports their hypothesis.
>This is a great tool for teaching the scientific method, and for clearing
>up points like how we know that electrons/protons/ions etc. actually
>exist.  Try it out, I think you'll enjoy it and so will the students.

I will - you lot now have me convinced - many thanks again for your helpful


:  Dr. Cris Woolston                                                      :
:  Department of Applied Biology                                          :
:  University of Hull, Cottingham Road, Hull HU6 7RX, UK                  :

:  RFC-822: C.J.Woolston at                       :
:  Tel:     +44 1482-465549  Fax:     +44 1482-465458                     :

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