The population sensitivity of vertical scaling results was evaluated for a state reading assessment spanning grades 3-10 and a state mathematics test spanning grades 3-8. Subpopulations considered included males and females. The 3-parameter logistic model was used to calibrate math and reading items and a common item design was used to construct the vertical scale. RMSD and REMSD values were computed for each grade. Results indicated more similar growth patterns across grades for gender subgroups for the mathematics assessments than for the reading assessments.