Determination of sample size for simple comparative experiments, determination of sample size to obtain a confidence interval of specified width, power of study, power of test, role of sample size in the calculation of confidence interval, importance of sample size determination in research, relationship between sample size and power of the study, relationship between sample size and confidence interval, effect of sample size on power of study, sampling errors, difference between statistics and parameter, non-sampling errors, types of samples, types of probability sampling, types of non-probability sampling