problem

Currently we do not have assigned the changes in a segment for a certain workflow-step to a certain user. See also https://confluence.translate5.net/pages/viewpage.action?pageId=576356353 for details.
due to increasing complexity this relation was cancelled in the original development.

Solution

According to Thomas, we already have the information which user has changed a certain segment in a certain workflow-step. If I understand it right, this information is stored in segment-history table. So this would be the perfect place to get the wanted information for Levenshtein-distance.

Only problem here:
when a segment is changed multiple times by multiple different user in one workflow-step, the changes can not be assigned to one user. For this edge-case we define, that all changes in this workflowstep will be assigned to the last user.

Sample:

Hello world
[changes by user_1] => Hello world !
[changes by user_2] => Hello world,

will end up in a Levenshtein-distance of 1, counted for user_2

That means, if I filter for user, all changes for segments within one workflow step would be attributed to the user, who saved the segment last. And as Levenshtein distance the distance to the state of that segment at the beginning of the workflow step would be taken into account.