Validation of assessments intended to improve instruction and learning should include evidence of instructional sensitivity. This study investigated the instructional sensitivity of a standards-based ninth-grade performance assessment that required students to write an essay about conflict in a literary work. Before administering the assessment, teachers of 886 ninth-grade students were randomly assigned to one of three instructional groups: literary analysis, organization of writing, and teacher-selected instruction. Despite the short duration of instruction (8 class periods), results support the instructional sensitivity of the assessment in two ways: Instruction on literary analysis significantly improved students' ability to analyze and describe conflicts in literature, and instruction on the organization of writing led to significantly higher scores on measures of coherence and organization. (Contains 9 tables. Appended are: (1) Example of Writing Group Lesson; (2) Example of Literary Analysis Group Lesson; (3) The English-Language Arts Grade 9 Performance Assessment Rubric; and (4) CRESST/LAUSD Instructional Sensitivity Study Score Sheet.)