Since the early 1980s, ASGW (Association for Specialists in Group Work) has promulgated standards for training group workers. Now, in their third revision, these standards establish core group work knowledge and skills to be included in all counselor training programs. To advance research on the relationship between mastery of ASGW's core knowledge and other group training and outcome phenomena, the ASGW Training Standards Committee developed the Core Group Work Skills Inventory-Importance and Confidence (CGWSI-IC) to assess an individual's valuing of and confidence in using the knowledge and skills embodied in the standards and assessed its psychometric properties. (Contains 4 tables and 1 figure.)