The Clark County Genealogical Society presents “Cleaning Up the Internet, One Lineage at a Time” from 10 a.m. to noon May 6 at the society’s headquarters, 3205 N.E. 52nd St., Vancouver. This presentation focuses on how to examine what others have posted online in order to make an enlightened decision on whether those lineage claims are based on fact or fiction. Attendees are encouraged to share online family trees they have encountered. All attendees will use the presentation’s insights and techniques to evaluate the tree. Attendees are invited to bring lunch or snacks. The cost is $15 for members or $20 for non-members. Sign up at ccgs-wa.org/activities/classes/.