# Dimension level summary statistics

It is possible to view **Dimension Level Summary Statistics** on a Profile report. These statistics rank the overall power of the dimension as a predictor.

Right clicking on a column header allows you to add the statistical measures **Phi** and **Cramer’s V**.

## Dimension column summary

- **Mean Index** - weighted mean of (equivalent positive) Index across significant categories
- **Min Index** - min of Index across significant categories
- **Max Index** - max of Index across significant categories
- **Mean PWE** - weighted mean of the absolute PWE scores across significant categories
- **Mean Z Score** - weighted mean of the absolute Z scores across significant categories
- **Phi** & **Cramer’s V** - standard statistical measures

The **Mean Index**, **Mean PWE** and **Mean Z Score** are all weighted by the proportion of analysis records in each category.

Categories that are not significant (have not reached the threshold Z-Score) are excluded.

The weighting reflects the distribution across the categories and prevents a large index that only applies to a small number of records dominating the summary result.

To calculate the **Mean Index** for each category, we first take the equivalent positive Index.

Combining directly **positive (100-infinity)** and **negative (100-0)** indexes together makes no sense as they use different log scales. Therefore, \**(100/Index)*100** is used to convert from a negative to a positive index.

## Example: Calculating mean index

The example below relates to the Gender Dimension - see screenshot above - and explains how the **Mean Index of 193.31** was derived.

- Female: ZdExp \> 3 significant → category index 52.10 convert to positive index (100/52.10)\*100 = 191.92 weight by 8674/25175 → 66.13
- Male: ZdExp \> 3 significant → category index 195.39 weight by 16101/25175 → 124.97
- Unknown: ZdExp \> 3 significant → category index 139.32 weight by 400/25175 → 2.21
- Summing across categories 66.13 + 124.97 + 2.21 → 193.31