The Silly
Season continues in Universities as the talking points and marketing material
are generated. Leagues table updates are out and everyone rushes to
interpret the last data point. The disease propagates from the League table
publishers to the universities, the government, the media and Mr and Mrs
Somewhat-above-average. What is so silly? That the last data point is
interpreted at the expense of longer term better data sets. If you do this,
remember...
The Excursions May Be Great but Mostly They
Stay the Same. Looking
again at the data set of 5 selected Universities (Derby, Nottingham, Nottingham
Trent, Sheffield and Sheffield Hallam) it is worth considering the 5 year
average, the median, and the standard deviation as well. In all cases the
median values are very close to the averages and while there is some skew
(asymmetry) to the data mostly they are just randomly fluctuating about a mean.
University
|
Average League Table
Position
|
Standard Deviation
|
Median
|
Derby
|
100
|
8.1
|
103
|
Nottingham
|
20
|
3.1
|
19
|
Nottingham Trent
|
56
|
5.6
|
55
|
Sheffield
|
26
|
1.1
|
26
|
Sheffield Hallam
|
69
|
5.4
|
68
|
University marketing materials use this
material ONLY when it is in their favour to do so. They do not give equal
weight to downward results. If you listen, at best you are making a decision on
a biased presentation of flimsy data because over 5 years or so, they are reasonably
stable about a mean value. If they generally stay the same while you are earning your degree, you should ignore league tables and make your
decision in other ways.
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