Abstract

This two-class quasi-experimental pilot documented class-level score patterns before and immediately after a four-week recycling and upcycling STEM-PBL unit in three self-reported components of environmental literacy among fourth-grade students in an Arabic-speaking school in northern Israel. Two intact classes (N = 62), with one class per condition, received either STEM-PBL instruction (n = 32) or teacher-led comparison instruction (n = 30). The intervention, conducted during regular science lessons, engaged small groups in relevant design challenges integrating measurement, materials, tool use, and engineering constraints. STEM was treated as an instructional design approach rather than an achievement outcome, and implementation fidelity was not independently assessed. Outcomes were measured using an age-appropriate three-point questionnaire assessing positive environmental behavioral tendencies, awareness and perceived knowledge, and negative environmental behavioral tendencies. Because the same students completed pre- and post-unit questionnaires, but anonymous responses could not be linked, observations were repeated but unpaired; therefore, inferential pre-posttests and standardized effect-size estimates were not used. Descriptively, the experimental class showed more favorable post-unit means and larger raw mean differences than the comparison class across all three outcomes. These patterns do not establish individual change, causal effectiveness, or improvement in environmental literacy as a whole. Interpretation is further limited by one class per condition, immediate self-report measurement, marked ceiling and floor effects, possible content overlap and demand characteristics, and lack of fidelity evidence. The unit should therefore be viewed as a documented instructional example warranting replication across classrooms with delayed assessments, objective knowledge measures, behavioral indicators, and implementation-fidelity measures.