The purpose of instruction, whether face-to-face or online, is to facilitate student achievement of intended learning objectives. Traditionally, the major function of classroom assessment in undergraduate and graduate university courses has been to measure the individual student's learning in order to provide feedback to the student and to spread student scores (norm-referenced grading) to assign grades. Online assessments can measure the student's achievement of intended learning objectives if, and only if, great diligence is used in their construction. This paper will address the top ten issues in designing online classroom assessment: (1) measuring the objectives, (2) cognitive levels, (3) ethical considerations, (4) formative/summative, (5) criterion referenced /norm-referenced, (6) validity, (7) reliability, (8) diversity, (9) variety, (10) providing feedback.