<p><strong>Abstract:</strong> This study aims to explore students’ conceptual understanding of static fluid in STEM with e-formative assessment learning. The study uses embedded experimental design methods. It involved 30 students of XI grade high school in Sidoarjo. The pretest and posttest instruments consisted of 10 reasoning multiple chooise questions with reliability is 0.629. Wilcoxon test results is p = .000 with an average posttest higher than pretest shows that there is significant difference between students' conceptual understanding of before and after learning. The effect size value is 0.88. Students’ conceptual understanding of each indicator is also discussed.</p><strong>Abstrak:</strong><em> </em>Tujuan penelitian ini adalah mengetahui penguasaan konsep siswa pada materi fluida statis dalam pembelajaran STEM disertai <em>e-formative assessment</em>. Penelitian menggunakan <em>mixed method</em> desain <em>embedded experimental</em>. Penelitian melibatkan 30 siswa kelas XI SMA di Sidoarjo. Instrumen <em>pretest</em> dan <em>posttest</em> berupa 10 soal penguasaan konsep pilihan ganda disertai alasan dengan reliabilitas 0,629. Hasil uji Wilcoxon sebesar <em>p</em>=.000 dengan rata-rata <em>posttest</em> lebih tinggi daripada <em>pretest</em> menunjukkan bahwa terdapat perbedaan yang signifikan antara penguasaan konsep siswa sebelum dan sesudah pembelajaran. Nilai <em>effect size</em> sebesar 0,88 menunjukkan bahwa pembelajaran STEM disertai <em>e-formative assessment</em> berpengaruh sedang terhadap penguasaan konsep. Penguasaan konsep siswa setiap indikator juga akan dibahas.

This study aims to explore the scientific creativity of high school students on the static fluid in STREM PBL with an e-authentic assessment. This study used a mixed method with an embedded experimental design. This study involved 30 11th-grade senior high school students in Sidoarjo, Indonesia. Data collection techniques were carried out through pretest-posttest, interview, and observation. Pretest and posttest instruments consist of three scientific creativity essay questions with a reliability of 0.610. The results of the Wilcoxon test of p = .000, with the posttest being higher than the pretest, indicate a significant difference between students’ scientific creativity before and after learning. The effect size value of 0.87 indicates that STREM PBL with an e-authentic assessment moderately affects students’ scientific creativity. All indicators of scientific creativity have increased. The order of increasing the average scientific creativity score for each indicator is fluency (high) elaboration (moderate) originality (moderate) flexibility (moderate). Meanwhile, the order of the average level of scientific creativity at the posttest is fluency (very creative) elaboration (quite creative) = flexibility (quite creative) originality (less creative). Students’ scientific creativity increases because this learning makes students solve problems, carry out projects (design and create a product), carry out inquiry activities (experiment and investigation), collaborate with groups, and evaluate projects through self and peer assessment. Learning activities that can increase the level of fluency indicators are mentioning as many ideas as possible for experimental designs and product designs. Learning activities that can increase the level of flexibility indicators are integrating religion content into STEM (it is also better if integrating art content) and providing several problems and products from various fields. Learning activities that increase originality indicators give each individual or group a different project topic. Learning activities that can increase elaboration indicators are strengthening mastery of concepts and evaluating the work of oneself and others through self-assessment and peer assessment.

Penelitian ini bertujuan untuk menguji efektivitas e-formative assessment dalam meningkatkan penguasaan konsep siswa pada materi fluida statis. Penelitian dengan metode one group pretest-posttest design ini melibatkan 30 siswa. Instrumen pretest dan posttest terdiri atas 10 soal pilihan ganda disertai alasan dengan reliabilitas 0,629 dan level kognitif dari C3-C5. Instrumen tes formatif yang diberikan terdiri atas 10 soal pilihan ganda dengan indikator dan tingkat kesulitan setara dengan pretest dan posstest. Hasil uji Wilcoxon menunjukkan bahwa rata-rata nilai posttest secara signifikan lebih tinggi daripada rata-rata nilai pretest (p=.000). Nilai effect size sebesar 0,88 menunjukkan bahwa e-formative assessment berpengaruh sedang terhadap penguasaan konsep siswa pada materi fluida statis. Salah satu faktor penentu e-formative assessment dapat meningkatkan penguasaan konsep siswa adalah adanya pemberian feedback. Melalui feedback, miskonsepsi yang dialami siswa dapat segera dibenarkan. E-formative assessment yang diberikan melalui web juga semakin efektif dalam memberikan feedback yang cepat dan tepat kepada seluruh siswa dengan beragam respon.