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Error Rate Defined: Error rate is the expected error associated with a sampling technique, based on sample size and response rate. Please examine the text below the calculator for usage instructions.

KEY INPUT VARIABLES
Number of interviews: Number of respondents answering a particular question
Population: Total population the survey is intended to represent; the number of possible interviews that could be done (e.g. total patient population, total number of medical staff members, population of adults for the defined service area).
Infinite Population: Use this designation if the total population is 10,000 or more (e.g. for consumer studies, community health assessments, etc.)
Response Error		Number of Interviews
Number of Interviews Population Specific Response Error Infinite Population

Error Rate Usage Instructions: To calculate the error rate associated with a particular number of responses within a study, select the Response Error feature. Type in the number of responses in the Number of Interviews box, then either type in the total number of survey respondents in the Population box or check the Infinite Population if you have an infinite population. Once you click the Calculate button, your Specific Response Error will appear.

Example: If we had 250 respondents to a particular question, out of 350 total survey respondents, we would type 250 in the Number of Interviews box and 350 in the Population box. By clicking on the Calculate button, we would see that our Error Rate is +/- 3.3.

Number of Interviews Usage Instructions: To determine how many interviews you need to conduct to achieve a certain error rate, first select the Number of Interviews feature. Then type your total population in the Total Population box and the desired error rate in the Specific Response Error box. If your total population is infinite, check the Infinite Population box. By clicking on the Calculate button, the number of interviews you need to conduct to achieve your desired error rate will appear in the Number of Interviews box.

Example: If we wanted to achieve an error rate of 1.5, and we had an infinite population, we would click the Infinite Population box, then enter 1.5 in the Specific Response Error box. By clicking on the Calculate button, we would see that we need to conduct 4268 surveys to achieve an error rate of +/- 1.5.