The Active Lives data are collected from a survey, meaning all figures calculated are estimates and contain a margin of error – the confidence interval.
Confidence intervals indicate that if repeated samples were taken and confidence intervals computed for each sample, 95% of the intervals would contain the true value.
Confidence intervals are important to consider when it comes to analysing the Active Lives dataset, especially when drawing out inferences from the data. A figure with a wide confidence interval may not be as robust a statistic as one with a narrow confidence interval.
Confidence intervals vary for each measure and each demographic breakdown and will vary from year to year. Confidence intervals should be calculated using the complex survey package in SPSS, which takes account of design effects.