ABSTRACT
A sample of data can be difficult to comprehend; it is often difficult to see a trend in a set of numbers. Various procedures are used to aid the understanding of data. Graphs, histograms, and various diagrams can be of help. Some middle or average value, a measure of the central tendency of the numbers, is useful. An average or mean of a sample of scores is a middle value or a measure of central tendency. When dealing with the interpretation of any form of average data, care must be taken so that the hidden assumption that it represents the data of each individual is not inadvertently made. Variances and standard deviations are generally used with means and, like the mean, can be misleading unless the numbers are spread symmetrically. When the distribution of numbers is skewed, medians and interquartile ranges may be more useful descriptions.
