Technical Features of Sentence-Level Curriculum-Based Measures and Language Sample Analysis for Students With Writing Difficulties

Given oral language's role in writing proficiency and to address measurement issues in oral and written language, we trialed complementary scoring metrics in language sample analysis (LSA) with the sentence-level Picture Word Writing Curriculum-Based Measure (CBM-W). Using the Picture Word CBM-W samples of 123 students with writing difficulties, we investigated (1a) alternate form reliability, (1b) criterion-related validity with existing Picture Word CBM-W metrics, (2) criterion-related validity with a standardized written expression measure, and (3) sensitivity to growth from fall to spring for LSA and Picture Word CBM-W scoring mechanisms. Pearson product-moment correlations, Spearman's correlations, and Bonferroni-corrected paired-samples <i>t</i>-tests revealed two promising LSA metrics with evidence of technical quality and sensitivity to growth as a complementary scoring mechanism for Picture Word CBM-W: mean length of T-Unit in morphemes (MLTU-M) using the mean of two forms in the fall, and number of different words (NDW) using the mean of two forms in fall and spring. Results support the role of oral language in sentence-level writing proficiency, as well as MLTU-M and NDW as complementary scoring mechanisms to provide more specific estimates of oral language skills in grammar/morphosyntax and semantics/lexical diversity not possible with current Picture Word CBM-W scoring mechanisms.