Development of Electronic Portfolio-Based Assessment Strategies in Chemistry Learning to Assess Students' Concept Mastery

Abstract

This study aims at developing an electronic portfolio-based assessment strategy as valid and reliable assessment for learning on colloidal system material to measure student concept mastery. This study used a Design-Based Research (DBR) with a 4D development model that is carried out until stage 3 (Define, Design, and Development). The participant in this study were 10 students of class XI in one of High Schools in Bandung who were involved in the limited trial phase. The concept mastery ability measured in this study used the Revised Bloom's Taxonomy framework. However, the researcher only used the cognitive level of applying (C3) and analyzing (C4) based on the analysis of Core Competence and Basic Competence in the syllabus for colloidal system material. The tasks developed in this electronic portfolio assessment consist of three tasks, namely a concept map of the types of colloids; papers on the properties of colloids, the application of the properties of colloids in life, and how to make colloids; and a practical simulation report on the colloidal properties of the Tyndall effect. The results showed that the instrument was valid with a CVR value of 0.6 - 1.0 and reliable with a Cronbach Alpha value of 0.679 - 1.000. Based on the results of a limited trial of the developed electronic portfolio-based assessment strategy, it can measure student concept mastery on colloidal system material. Overall, the average level of student concept mastery is categorized as good. With details in the category of very good (30%), good (50%) and sufficient (20%).