Percentages and proportions supply frame of reference for reporting research results in the sense that they standardize the raw data: percentages to the base 100 and proportions" to the base 1. 00. Percentages and proportions are easier to read and comprehend than frequencies: particularly obvious when attempting to compare groups of different sizes. Computing percentages eliminates the difference in size of the two groups by standardizing both distributions to the base of 100. Guidelines on use of percentages and proportions: when working with a small number of cases (i. e. less than 20), it is preferable to report the actual frequencies rather than percentages or proportions. Percentages can change drastically with relatively minor changes in data: always report number of observations along with proportions and percentages. Permits reader to judge adequacy of the sample size: percentages and proportions can be calculated for variables at ordinal and nominal levels of measurement, even though they require division.