Contributed by: Assessment of Performance Unit
1989 Administration
General Considerations
Until the purpose of the observation becomes clear, i.e. until
the student reads part 2, then any varying attribute of the strings,
such as color, diameter, material, or tension, could be recorded.
Students who do not record, say, color, either do not see any difference
between the strings, or may have read part 2 before completing part
1. They presumably reject color on the grounds of relevance and
so they are applying their scientific knowledge to the question.
Part 2 is about identifying relevant variables - frequency first,
string diameter second, and then describing their relationship,
i.e. sound frequency varies with string diameter, the direction
of the relationship necessary so that "as the diameter of the string
increases, so the frequency of the sound decreases" becomes the
type of answer expected.
|