PENGARUH PEMBELAJARAN KOLABORATIF BERBASIS PROYEK TERHADAP KETERAMPILAN KOMUNIKASI SISWA SMP NEGERI 4 PALU

Abstract: The low communication skills of students in conventional biology learning remain a critical concern. This
study analyzed the effect of collaborative project-based learning (PjBL) on communication skills of students at SMP
Negeri 4 Palu, measured across four indicators: expressing opinions, summarizing information, giving instructions,
and motivating group members. A quasi-experimental nonequivalent control group design was employed, involving
22 experimental and 24 control students selected through cluster random sampling. The intervention used a
contextual Eco-Soil Poster Campaign project on soil health conservation. Communication skills were collected via
posttest questionnaire, while a cognitive pretest verified initial group equivalence. The instrument was validated
using Aiken's V and Cronbach's Alpha. Results revealed a significant difference between groups (p = 0.018 < 0.05),
with the experimental group scoring higher (75.64%, Good) than the control group (69.83%, Fair), with a moderate
effect size (Cohen's d = 0.724). PjBL significantly affects students' communication skills and is recommended in
junior high school biology education.
Keywords: communication skills, Eco-Soil Poster Campaign, PjBL, junior high school students, quasi-experimental