This is important research for anyone who performs observational postural assessments. Researchers Bao, Howard, Spielholz, Silverstein, and Polissar conducted a study designed to investigate interrater reliability -- the ability of different observers/assessors to reach the same conclusions when visually estimating posture. Their results indicate that the nature of the assessment tool, large angle categories vs. small angle categories in particular, and the experience and training of the assessor can have significant impacts on reliability.