This article shown the validity and reliability of instrument to measure the quality of academic assessment CALA, using dimensions of servqual, quality service model. Objective is the evaluation of perception about the quality of academic assessment through a virtual platform in elementary school institutions. The methodology follows validation of descriptive studio of multidimensional scales, design quasi experimental, factorial analysis technique. Sample was constituted by 1117 students of elementary school institution with mean age of 9.6 years old. Results: 24 indicators in satisfaction dimensions in availability of contents – didactic resources, feedback-follow-up, accessibility, comfort, proper internal consistency α=0.9 (Conbrach, 1951), global intra class correlation coefficient 0.8 (IC of 95%, 0.78 0.82) and Kappa indexes (Cohen, 1960) superiors to 0.78, shown a highly concordance between experts.