# Available Statistics and Assertions

## Statistics

<table><thead><tr><th width="330.54296875">Statistic</th><th>Description</th></tr></thead><tbody><tr><td>absolute difference of max</td><td>-</td></tr><tr><td>absolute difference of mean</td><td>-</td></tr><tr><td>absolute difference of median</td><td>-</td></tr><tr><td>absolute difference of min</td><td>-</td></tr><tr><td>absolute difference of percentile</td><td>Requires <code>percentage</code> as a parameter.</td></tr><tr><td>absolute difference of standard deviation</td><td>-</td></tr><tr><td>absolute difference of sum</td><td>-</td></tr><tr><td>Category Rank Discrepancy</td><td><p>Computes the absolute difference in the proportion of the specified category between the experiment and baseline runs. The category is specified by its rank in the baseline run.</p><p></p><p>Requires <code>rank</code>as a parameter:  can be one of [<code>most_common, second_most_common, not_top_two]</code>.</p></td></tr><tr><td>Chi-squared stat, scaled</td><td>Computes a scaled and normalized <a href="https://en.wikipedia.org/wiki/Chi-squared_test">Chi-squared</a> statistic between two nominal distributions.</td></tr><tr><td>Kolmogorov-Smirnov stat, scaled</td><td>Computes a scaled and normalized <a href="https://en.wikipedia.org/wiki/Kolmogorov%E2%80%93Smirnov_test">Kolmogorov-Smirnov</a> statistic between two ordinal distributions.</td></tr><tr><td>max</td><td>-</td></tr><tr><td>mean</td><td>-</td></tr><tr><td>median</td><td>-</td></tr><tr><td>min</td><td>-</td></tr><tr><td>mode</td><td>-</td></tr><tr><td>Null Count</td><td>Computes the number of <code>None</code> values in a column.</td></tr><tr><td>Null Percentage</td><td>Computes the fraction of <code>None</code> values in a column.</td></tr><tr><td>percentile</td><td>Requires <code>percentage</code> as a parameter.</td></tr><tr><td>scalar</td><td>Special function for using <a href="../../../runs/reporting-runs#scalars">scalars</a> in tests. Returns the input as a scalar value if it is a scalar and returns an error otherwise.</td></tr><tr><td>signed difference of max</td><td>-</td></tr><tr><td>signed difference of mean</td><td>-</td></tr><tr><td>signed difference of median</td><td>-</td></tr><tr><td>signed difference of min</td><td>-</td></tr><tr><td>signed difference of percentile</td><td>Requires <code>percentage</code> as a parameter.</td></tr><tr><td>signed difference of standard deviation</td><td>-</td></tr><tr><td>signed difference of sum</td><td>-</td></tr><tr><td>standard deviation</td><td>-</td></tr><tr><td>sum</td><td>-</td></tr></tbody></table>

## Assertions

| Assertion                |
| ------------------------ |
| between                  |
| between or equal to      |
| close to                 |
| equal to                 |
| greater than             |
| greater than or equal to |
| less than                |
| less than or equal to    |
| not equal to             |
| outside                  |
| outside or equal to      |