The Report of the National Academy of Sciences Monitoring International Labor Standards: Techniques and Sources of Information shows that assessing compliance can be carried out in a thorough, transparent fashion, allowing alternative evaluators to identify where they disagree in assessment. Drawing on the Report and written by the Chair of the Committee that produced it, this paper offers a short overview of the principal challenges in assessing compliance with the ILO core labor standards, and offers a simple framework for investigating compliance. The paper concludes with a discussion of the implications for trying to include labor standards in trade agreements.