Confidence Interval

Quantitative research in educational psychology benefits from using sample data to describe the wider population of interest. A confidence interval (CI) is a statistical approach that uses sample data to determine a range of values on a particular statistic (e.g., mean) for a sample from the population. In theory, a confidence interval is based on an infinite number of random samples from the population. For each of these random samples, a statistic of interest, such as the mean, could be calculated. Of course, it is highly unlikely that each of these means will be equal to one another, and even more unlikely that any or all of the means will equal the population mean. Thus, it is generally safe to assume that error will be ...