These include the cost to design the survey, analyze the results and write a final report. Fixed costs usually represent a major portion of the budget. Variable costs increase with increases in sample size. Variable costs include printing, collecting and entering data. Time - Time constraints may restrict the number of persons surveyed.
Statisticians use various formulas to calculate sample size.
However, you may want to survey more than two sub-groups, such as different school districts, age categories or income levels. To ensure a representative number of observations in a sub-group, determine the actual size of that subgroup and use Figure 1 to estimate a sample size for that subgroup. Response Rates Poor response rates are a serious problem in any survey. A needs assessment survey with a low return rate may not accurately represent the population. It is important to contact members of the original sample and request that they complete the survey.