A review of statistical philosophy in biologic research focusing on occupational health and public health dentistry was presented. Causation and the principle of relevance, as well as the need for statistical methods in biologic research were discussed. Collection of data, classification and tabulation, and summarization by means of derived constants were considered. Topics included: ratio, rates, frequency, frequency rate, percentage, probability, multiple events, and rate of change. Dichotomous classification, continuous and discrete variables, and frequency distribution were discussed. Centering constants, constants of dispersion, standard deviation, calculation of mean and standard deviation, and mean and standard deviation related to normal curve were described. Measurement of industrial illness, focusing on disabling illness, was discussed. The statistical philosophy underlying sampling was presented for the following applications: comparison of arithmetic means, percentages, and rates involving multiple events, and calculation of correlation coefficient, as well as size of sample. The author concludes that a critical attitude is necessary as a prerequisite for arriving at conclusions derived from quantitative data; also, statistical guidance in the design of studies and the analysis of data is necessary.