StarStat is a free statistical calculator designed to easily perform tests of statistical significance on your survey data.

Survey researchers use significance testing as an aid in expressing the reliability of survey results. Phrases such as "significantly different," "margin of error," and "confidence levels" help describe and make comparisons when analyzing data.

The purpose of this free tool is to aid researchers in performing appropriate statistical tests for data analysis.

StarStat includes 3 different tests:

Z-test Calculator:
The z-test of proportions is used to test the difference between proportions (percentages) for two groups. Statistics computed provide the probability that a difference at least as large as noted would have occurred by chance if the two population proportions were in fact equal.

T-test Calculator:
The t-test of independent means is used to test the difference between means for two groups. Statistics computed provide the probability that a difference at least as large as noted would have occurred by chance if the two population means were in fact equal.

Sample Precision Calculator:
Sample precision or margin of error calculations determine a conservative estimate of sampling error for a given sample size. These estimates are helpful in answering questions like: "How large a sample do I need?" or "How reliable are my survey results?"

StarStat was developed by DataStar, Inc., a leading provider of survey management and data processing services, specializing in web surveys for employee and customer feedback. For more information, contact us at www.surveystar.com.