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CHAPTER
1
Critical thinking and problem solving
5
be harmful to health (untrue: when orthodox medicine fails, patients are more
seriously ill).
• Confusion over percentages and numbers. For example, 15 per cent of road fatal-
ities involve motorbikes and 75 per cent involve cars so it is five times safer to ride
a motorbike than to drive a car (untrue: fewer than one in 50 vehicles are motor-
bikes).
• Over-generalizing. For example, nine out of 10 people interviewed said
they would buy a small car next time so there is little market for the large car
(sample too small or unrepresentative; all those interviewed drove small cars).
• Logical fallacy: the premises are true but do not support the conclusion (though
it may be true). For example, if A follows B (true) then so must C, D and E (false).
Note that a true conclusion can be arrived at (accidentally) with false premises.
Questions in the IMAT take various forms:
• A short paragraph that contains a conclusion and the evidence that supports
it. You should assume that the evidence (premises) is true for the purposes of
the argument; ie, do not introduce your own knowledge base or opinions. Choose
an answer that:
– is the
best conclusion
(ie the main thrust of the argument or what can be safely
inferred
), or
– identifies what has been
implied
(not directly stated or assumed, but suggested
or hinted at), or
– identifies what
must be assumed
for the conclusion to hold true, or
– would
weaken
the argument if it were true (ie contradictory statement;
alternative explanation), or
– would
strengthen
the argument if it were true (ie supportive statement;
consistent), or
– would show the conclusion to be untrue (eg a
fallacy
).
You need to analyse the argument in order to distinguish between the conclusion and
the supporting reasons, together with any contextual information that may be
included in the passage.
Some questions test a combination of skills, or approach the problem from a different
perspective, so you could be asked to: clarify an ambiguous term, explain an anomaly
or discrepancy, describe the logical function of a word or phrase, assess a definition,
or supply a missing piece in a chain of reasoning.
Of course, in order to answer correctly, a background of semi-technical knowledge is
assumed: this includes terms such as
premise
,
assumption
,
reason
,
explanation
,
inference
,
implication
,
consequence
and
conclusion
. You will be expected to distinguish between
necessary
and
sufficient conditions
,
general
and
particular statements
,
cause
and
correlation
,
and to recognise relations such as
consistency
,
contradiction
,
compatibility
and
equiva-
lence
.