Validation of a scheme for assessing argumentative writing of middle school students

Two studies tested factors influencing ratings of argumentative essays in order to develop a scheme for assessing essays written by middle school students. Study CLAIM-CLARITY assessed the effect of: (a) claim clarity, (b) reason strength, (c) strength of rebuttals to counterarguments, (d) the rater's personal values, and (e) the rater's topic knowledge. These factors explained a third of the variance in holistic scores. There was a significant interaction between raters' topic knowledge and the validity of evidential statements. Raters' values were not significant with respect to the range of topics included in this study. Study DEVELOPMENT assessed the effect of: (a) development, (b) voice, and (c) conventions. The factors explained 63 percent of the variance in holistic ratings. This result was attributed to an assessment scheme that fostered integrated rather than isolated consideration of argument elements.