Writing Evaluation: Rater and Task Effects on the Reliability of Writing Scores for Children in Grades 3 and 4

Abstract

We examined how raters and tasks influence measurement error in writing evaluation and how many raters and tasks are needed to reach a desirable level of .90 and .80 reliabilities for children in Grades 3 and 4. A total of 211 children (102 boys) were administered three tasks in narrative and expository genres, respectively, and their written compositions were evaluated in widely used evaluation methods for developing writers: holistic scoring, productivity, and curriculum-based writing scores. Results showed that 54% and 52% of variance in narrative and expository compositions were attributable to true individual differences in writing. Students' scores varied largely by tasks (30.44% and 28.61% of variance), but not by raters. To reach the reliability of .90, multiple tasks and raters were needed, and for the reliability of .80, a single rater and multiple tasks were needed. These findings offer important implications about reliably evaluating children's writing skills, given that writing is typically evaluated by a single task and a single rater in classrooms and even in state accountability systems.

Keywords: Generalizability theory; assessment; rater effect; task effect; writing.

Figure 1

Generalizability and phi coefficients of holistic scores as a function of raters and tasks: Y axis represents reliability; X axis represents number of tasks; lines represent number of raters from one rater (lowest line) to seven raters (highest line)

Figure 2

Generalizability and phi coefficients of number sentences as a function of raters and tasks: Y axis represents reliability; X axis represents number of tasks; lines represent number of raters from one rater to seven raters (lines largely overlap due to small rater effect)