Lost ties in CCK08 forum 1

I've reassessed my findings in this post: http://paaralan.blogspot.com/2009/07/validating-aneesha-bakharias-sna-moodle.html. In it I tried to estimate the reliability and validity of the Moodle forum SNA Tool.

In forum 1 of CCK08, 78 ties were identified by the tool. 4 ties were found in the body of the post that were not identified. Therefore of the total ties (82),  4.88% were lost.

But that is conveniently sampled. I really do not know how many ties on the average are lost for all the forums.