Summary: In the spring of 1998, federal agencies submitted their first annual performance plans under the Government Performance and Results Act. GAO found that many of these initial performance plans faltered at their central task: developing measurable goals for the results or outcomes that their programs are intended to achieve. A common challenge for many federal agencies is to develop goals for outcomes that are the results of phenomena outside of the government's control. Indeed, many, if not most, federal programs seek to improve complex systems, such as the economy or the environment, or share responsibilities with other agencies for achieving their objectives. As a result, they confront the challenge of setting goals that are both far-reaching and can be realistically affected by the programs. To help agencies identify methods for developing such goals, GAO examined six programs--the Job Training Partnership Act, the National Highway Traffic Safety Administration, the Natural Resource Conservation Service, the Occupational Safety and Health Administration, the Safe Drinking Water Program, and Title I: Education Assistance--as case studies of how agencies were able to develop performance measures for outcome goals that are affected by external factors. GAO discusses the strategies that these six programs used to set outcome goals.