Top dimension items and top segments difference scores

To compute the difference score on the Top Dimension Items and Top Segment Difference tables, a relative risk differencing algorithm is used (similar to risk ratio, although using a difference rather than a ratio). A risk difference is calculated by subtracting the cumulative incidences of a dimension item (or overlap with a segment from the segment table) of one selected segment from the other. A high difference score (close to 1) means the particular dimension item or tertiary segment was very prominent in one of the selected segments and not the other.

NOTE
In all three tables, the difference statistic is based on an appropriate sample of visitors to make the process run as quickly as possible while remaining statistically accurate. While the difference score is based on a sample, the results presented in the table are not sampled. To ensure statistical significance, each statistical test relies on a dynamic allocation algorithm such that the smaller segment contains a sample size that provides less than 3% margin of error. If a segment contains very few visitors (less than 1,000), we use all available data and do not sample in computing the difference score.

Analytics