Understanding and Using Descriptive Statistics

Abstract

There is sometimes confusion over the correct statistical techniques that should be used in a particular setting. This paper outlines some methods that can be applied both to display information graphically and to summarise data numerically. The relative strengths and weaknesses of a number of diagrams and summary measures are examined. The particular method(s) that is used depends upon a number of factors. These are, firstly, the level of measurement of the data that have been collected; secondly, the overall distribution of the data being investigated; and, finally, the overall strategy of the plan of investigation. The reasons as to why a particular technique should be used are not always apparent and some methods for making a decision are discussed. Investigators should consider their choice carefully and be in a position to justify that choice.