In this study, conceptual and algebra-based physics students were engaged in scientific inquiry using Physics Education Technology (PhET) interactive simulations via semester-long group projects. The instructor and students used the Scientific Abilities Assessment Rubrics (SAAR) to evaluate project presentations and papers (formative assessment). The overall research project was evaluated using Lab Skills Self-Assessment (LSSA) survey (pre and post) and the post reflection survey. The Science Process Skills Inventory (SPSI) was used to analyze some of the students‟ responses to the reflection survey. Quantitative analysis of the LSSA survey showed a large effect size for both conceptual and algebra-based physics students (Cohen‟s d > 0.8, in both courses). Qualitative analysis of the reflection surveys supported this apparent huge gain in lab skills and revealed considerable positive students‟ experiences of the PhET simulations (88% of students indicated positive satisfaction).