Virtual Laboratory Development with Student's Worksheet to Improve Critical Thinking on Electrochemistry for Vocational School Students

Vocational schools graduate students who are work-ready for the industries. In the era of Industrial Revolution 4.0, the critical thinking is needed. This research was aimed to develop the virtual laboratory with student's worksheets to improve students' critical thinking. The product, Virtual Laboratory with Student's Worksheets (VLSW), was expected to increase students' critical thinking after they had finished the lesson. Research and Development methods proposed by Borg and Gall were used in this research. The VLSW validation sheets were used as the instrument. The Delphi technique with eight experts was to validate virtual laboratory and student worksheets. The content validity by Aiken showed 0.94 for virtual laboratory while 0.90 for student worksheets. Therefore, virtual laboratory and student's worksheets can then be used in electrochemistry learning. One hundred eighty tenth grade students from three vocational schools in Surakarta, Indonesia were used as samples. The average of the students' responses to the content, presentation, language, and the chart was 92%, while student worksheets was 87%. The result of the paired sample t-test showed that VLSW significant to improve critical thinking for high and middle vocational schools, but not significant for low category vocational school. Development of learning media on other chemical concepts is needed to improve students' critical thinking skills.