Summary of Measures of Central Tendency (1 of 2)

Of the five measures of central tendency discussed, the mean is by far the most widely used. It takes every score into account, is the most efficient measure of central tendency for normal distributions and is mathematically tractable making it possible for statisticians to develop statistical procedures for drawing inferences about means. On the other hand, the mean is not appropriate for highly skewed distributions and is less efficient than other measures of central tendency when extreme scores are possible. The geometric mean is a viable alternative if all the scores are positive and the distribution has a positive skew.

The median is useful because its meaning is clear and it is more efficient than the mean in highly-skewed distributions. However, it ignores many scores and is generally less efficient than the mean, the trimean, and trimmed means.

The mode can be informative but should almost never be used as the only measure of central tendency since it is highly susceptible to sampling fluctuations.

Click here for an interactive demonstration of properties of the mean and median. next