Statistics for the Terrified: Glossary
Click on an item below to see the definition
Mann-Whitney test:
The non-parametric equivalent of the two sample t test; essentially based on
the average rank observed in each group.
Mean:
An average, one of several that summarise the typical value of a set of data.
The mean is the grand total divided by the number of data points.
Mean square:
Appears as a column in an analysis of variance table and consists of what may
loosely be called the variance between the means for each factor.
Median:
The middle value in a sample sorted into ascending order. If the sample
contains an even number of values, the median is defined as the mean of the middle two.
Missing values:
The bugbear of many statistical experiments. This one really is what it sounds like!
Mode:
The most popular point of a distribution (that is, where the shape of the
distribution peaks).
Multiple regression:
This is linefitting with more than the two variables used in simple regression.
The techique is used to predict one variable with the assistance of two or more predictor variables.
See also Linefitting.
Multiple testing (multiplicity):
The more tests we do on the same data (eg. by subdividing the data into more and
more subsets) the more likely we are to find a significant result in one of them. Unfortunately this
is increasingly likely to be spurious because one in twenty tests on effectively identical populations will be
significant due to a type I error.
See also Type I error.
Mutually exclusive:
As an example, gender can be split into two
mutually exclusive groups; ie. a member of one cannot at the same time be a member of the other.
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