Several common sources of error in assessment that depends on the use of judges are identified, and ways to reduce the impact of rating errors are examined. Numerous threats to the validity of scores based on ratings exist. These threats include: (1) the halo effect; (2) stereotyping; (3) perception differences; (4) leniency/stringency error; and…

Research and evaluation staff members in schools and school districts are frequently called on to answer questions about the quality of schools. Responding merely with test scores is not sufficient, because it is important to communicate information about the total educational program in the district. Additional measures are available.…