**2. Objective**

This module would discuss the techniques of sampling, the fundamental concepts of probability, and the applications of probability theory. The role played by probability in modern science is that of a substitute for certainty, therefore definition of the probability is added, and the function of the probability distribution is discussed in the statistical theory, with reference to the normal distribution and its characteristics. Normal distribution is of great value in evaluation and research in both psychology and education, because it helps us to predict that where cases will fall within a distribution probabilistically. Variations of sampling and sampling types will be explained, along with the error of sampling, the standard error of the mean and the confidence intervals for determining the likely magnitude of the population mean. Generally, sampling allows researchers to obtain enough data to answer the research question(s) without having to query the entire population saving time and money. For this reason the major types of probability sampling methods and their characteristics would be addressed.
