Understanding of scientific concept about image formation by convex lens of students in Grade 12

This research aims to achieve the following objectives 1) Design and construct a test to measure understanding of the scientific concepts of image formation by convex lenses. 2) Explore the understanding of the scientific concept of image formation by convex lenses. The sample group consists of 30 Grade 12 students from a school in Nakhon Pathom. These students are enrolled in the Science-Mathematics program in semester 2 of the academic year 2023 and were selected individually. The research instrument is a test designed to measure understanding of the scientific concepts of image formation by convex lenses, which has passed quality checks. The test comprises 5 questions divided into 2 objectives. The survey revealed that, on average, 90% of students had discrepancies in their opinions. Specifically, the results indicated that students held misconceptions on 5 issues: drawing light rays from an object, drawing light rays refracting through a convex lens, drawing images from light rays crossing, identifying the type of image produced by a convex lens, and vision when an opaque sheet covers the convex lens, with percentages of 43%, 53%, 66%, 36%, and 47%, respectively.