Development of Experiment Performance Assessment Instruments using Guided Inquiry Learning Models to Assess Science Process Skills

This study aims to produce an experimental performance assessment instrument with guided inquiry learning model, prove the validity and estimate the reliability of instrument products, and determine the effectiveness of instruments to improve process performance. The method used is R & D (Research and Development) adopted from Dick et al which is divided into preliminary stage, planning stage, development stage, limited trial stage and extensive trial stage. Based on the results of the trial, the reliability of the rating results of the assessment instrument of science process skills were 0.707–0.989. The t-test results show that there is an improvement of science process skills. The results of this study are: (1) an experiment performance assessment product for science lesson of junior high school material of light properties, shadow formation, and working principle of optical instrument; (2) the experiment performance assessment instrument product has valid and reliable categories for assessing science process skills; (3) an effective experiment performance assessment instrument to improve science process skills.