Under TEC §39.036, TEA is required to develop a vertical scale for assessing student
performance in grades 3–8 mathematics and reading. A vertical scale allows for a student’s scale
scores to be compared across different grades for the same subject area. The changes in the
student’s vertical scale scores indicate the academic progress the student has made over time.
The assessments for which vertical scales were developed are STAAR grades 3–8 mathematics
and reading in English and STAAR Spanish grades 3–5 mathematics and reading.
In contrast, horizontal scale scores were developed for STAAR grades 4 and 7 writing, grades 5
and 8 science, grade 8 social studies, and EOC assessments. A horizontal scale converts a raw
score onto a scale that allows for comparisons across test forms from year to year for a specific
assessment. Similar to vertical scales, horizontal scales maintain the passing standard that
students are required to meet. However, unlike vertical scales, horizontal scale scores cannot be
compared to scale scores for other grades in the same subject area.