This report contains ratings of effective practices used to improve student success, retention, and completion, based on a Ruffalo Noel Levitz (RNL) electronic poll of undergraduate officials at U.S. colleges and universities in June of 2017. The report includes: (1) effectiveness rankings for 28 general strategies and tactics, such as one-on-one advising by professional staff and giving students practical work experiences in their desired major; (2) quality ratings for three leadership practices, such as the use of a committee and a written plan to guide efforts for student success/retention/completion; and (3) effectiveness ratings for 13 population-specific programs, such as programs for under-represented students and honor students.