Though we have advocated explicit argumentation instruction in science classes for decades, daily instructions are still found insufficient in improving students' argumentation competence. It is therefore important to explore effective instructional strategies through classroom research. This paper compares instructional strategies for classroom argumentation. We report on a quasi-experiment conducted with tenth-grade students (n = 92) that compares adversarial and parallel argumentation designs for the topic genetic inheritance, an inquiry-based socio-scientific issue (SSI) unit. The instruction was conducted through the online platform, Web-based Inquiry Science Environment (WISE). In the parallel design, student dyads were assigned to the same initial stances and were asked to change to multiple perspectives together, while in the adversarial design, students were assigned to opposite stances, and a debate was launched between the two sides. Students' overall argumentation performance improved significantly in both cases, yet the progress was greater in terms of counterarguments for students in the parallel design. Such findings highlight the value of parallel thinking in developing students' argumentation competence, especially in producing counterarguments. Suggestions on instructional design for scientific argumentation activities are proposed accordingly.

The COVID-19 pandemic caused many students away from the classroom. Its affecting region was so large and the inquiry learning had to move to online from offline. Although many studies had investigated the effectiveness of web-based inquiry learning, few of them conducted that under the pandemic. The pandemic took many new characters into education, such as the demand for the Internet. Hence, we conducted the pre-posttest quasi-experiment to investigate the effectiveness of online science inquiry during the pandemic. Under the instruction of teachers online, 30 fifth-grade students (19 males and 11 females) in a Chinese city completed a web-based inquiry learning program in the Web-based Inquiry Science Environment (WISE) platform. The experimental design ability test (EDAT) was conducted before and after web-based inquiry learning as the pre-test and post-test. The students’ attitude to web-based inquiry learning was also measured. The results showed, different from the studies before, the students’ score on experimental design ability decreased after web-based inquiry learning, especially in Asking Questions and Making Hypotheses subscales of EDAT significantly. No significant gender difference was detected. The students showed not a high attitude toward web-based inquiry learning. The possible factors causing that results and implications were discussed.