DOOSS supports ranking of structures by their one-dimensional or two-dimensional data values to assist the investigator in mining out structures which may be of the interest.
A structure is ranked by comparing the distribution of data values corresponding to the structure for a particular a data source against all data values for the same data source using a Mann-Whitney U test.
The Mann-Whitney U test generates a z-score which gives an indication of whether a particular structure lies at an extreme of the distribution of all data values in a data source. For example, a large negative z-score for a particular structure means that the median value for a structure is significantly less than the median data value for all data values in the data source, whereas a z-score close to zero indicates that the structure does not contain data values that are significantly different from the rest.
Structures that lie at an extreme (high or low z-score) are typically the most interesting.
Select Rank structures from the Analysis menu and then select the desired data source to rank against from the Data source menu.