Stats Refresher Flashcards
Describes the amount of variation in a distribution.
Measures of variability
Indicates how the scores in a distribution are scattered.
Variability
Difference between the highest and the lowest scores in a distribution.
Range
3 values that divide the set into four equal parts.
Quartile range
Difference between the upper and lower quartile.
Interquartile range
Measures variability equal to the square root of the average square deviations of the mean
SD
Arithmetic mean of the squares of the difference between scores and their mean in a distribution.
Variance
The distribution has a single peak.
Unimodal
Indicates how the measurements in a distribution are distributed.
Skewness
Score distribution is concentrated in the high end.
Negative skewed distribution
Score distribution is concentrated in the low end.
Positive skewed distribution
A statistical measure that defines how heavy the tail of a distribution and the peak of a frequency distribution.
Kurtosis
Distribution that follows a normal distribution.
Mesokurtic
Sharp peak with heavy tails distribution.
Leptopkurtic
Flat peak with lighter tail distribution.
Platykurtic
