Optimising e-portfolio marking strategies to improve validity, reliability, fairness, and time efficiency

Abstract

cohorts of optometry student portfolios (n=34) were analysed by a researcher who had no prior knowledge of the student’s work using a marking rubric of 10 domains, each marked using a 0-4 scale. Each portfolio consisted of an average 5 entries per week across 2 semesters. The portfolios were marked randomly one week every 3 months and then using progressively shorter intervals until every week had been marked. The progression of marks over time for each domain was also investigated.
Based on our student portfolio sample, the most time efficient marking interval that maintained acceptable levels of validity, reliability, fairness was 6 weeks every 3 months. This amounted to 35% of the total portfolio. Care however must be taken when assessing higher order skills with more weight given to the later part of the portfolio.