RESEARCH METHOD COHEN ok

416 TESTS
meet certain test items – reversing round a corner,
undertaking an emergency stop, avoiding a crash,
etc. – regardless of how many others have or have
not passed the driving test. Similarly many tests
of playing a musical instrument require specified
performances, such as the ability to play a particular
scale or arpeggio, the ability to play a Bach
fugue without hesitation or technical error. If the
student meets the criteria, then he or she passes
the examination.
A criterion-referenced test provides the
researcher with information about exactly what
astudenthaslearned,whatheorshecando,
whereas a norm-referenced test can only provide
the researcher with information on how well
one student has achieved in comparison with
another, enabling rank orderings of performance
and achievement to be constructed. Hence a
major feature of the norm-referenced test is
its ability to discriminate between students and
their achievements – a well-constructed normreferenced
test enables differences in achievement
to be measured acutely, i.e. to provide variability
or a great range of scores. For a criterion-referenced
test this is less of a problem: the intention here is
to indicate whether students have achieved a set
of given criteria, regardless of how many others
might or might not have achieved them, hence
variability or range is less important here.
More recently an outgrowth of criterionreferenced
testing has seen the rise of domainreferenced
tests (Gipps 1994: 81). Here considerable
significance is accorded to the careful and detailed
specification of the content or the domain which
will be assessed. The domain is the particular field
or area of the subject that is being tested, for
example, light in science, two-part counterpoint
in music, parts of speech in English language. The
domain is set out very clearly and very fully, such
that the full depth and breadth of the content are
established. Test items are then selected from this
very full field, with careful attention to sampling
procedures so that representativeness of the wider
field is ensured in the test items. The student’s
achievements on that test are computed to yield
aproportionofthemaximumscorepossible,and
this, in turn, is used as an index of the proportion
of the overall domain that she has grasped. So,
for example, if a domain has 1,000 items and
the test has 50 items, and the student scores 30
marks from the possible 50, then it is inferred that
she has grasped 60 per cent ({30 ÷ 50}×100) of
the domain of 1,000 items. Here inferences are
being made from a limited number of items to
the student’s achievements in the whole domain;
this requires careful and representative sampling
procedures for test items.
Commercially produced tests and
researcher-produced tests
There is a battery of tests in the public domain
which cover a vast range of topics and that can
be used for evaluative purposes (references were
indicated earlier). Most schools will have used
published tests at one time or another. There are
several attractions to using published tests:
They are objective.
They have been piloted and refined.
They have been standardized across a named
population (e.g. a region of the country, the
whole country, a particular age group or various
age groups) so that they represent a wide
population.
They declare how reliable and valid they are
(mentioned in the statistical details which are
usually contained in the manual of instructions
for administering the test).
They tend to be parametric tests, hence enabling
sophisticated statistics to be calculated.
They come complete with instructions for
administration.
They are often straightforward and quick to
administer and to mark.
Guides to the interpretation of the data are
usually included in the manual.
Researchers are spared the task of having to
devise, pilot and refine their own test.
On the other hand, Howitt and Cramer (2005)
suggest that commercially produced tests are
expensive to purchase and to administer; they are
often targeted to special, rather than to general
populations (e.g. in psychological testing), and