7.4 Reasoning with statistics 277
example. Statistics are powerful reasoning
tools. But what we infer from them needs to be
kept within bounds. When assessing statistical
reasoning, the big question is whether the
data is adequate for the claim or claims being
made.because crime rates have been falling, tough
sentencing is necessarily the explanation.
As far back as Unit 2 you were warned that
claims need to be measured so as not to require
too much from the reasons or evidence which
are given for them. This has been a useful
Summary
• Statistical data is a form of evidence
that can be used to support claims and
underpin arguments.
• There is a difference between raw data,
which is neutral, and data which has been
processed for a particular purpose.
• Selecting statistical data may reflect bias.
• Critical assessment of statistics involves
looking for ways in which presentation
can mislead, by exaggerating, simplifying,sampling selectively, etc. We must be
careful not to be ‘taken in’ by seemingly
impressive evidence.
• It also involves interpreting statistics fairly,
and assessing inferences that are made
on the strength of them. We should be
especially wary of inferences which are
too strong and/or too general, or which
assume a causal explanation from a mere
correlation or trend.