Using diffraction to measure hair diameter: An evidence-based evaluation of an alternative Physics laboratory activity in Biophysics

Abstract

A ruler is a common instrument of measurement that displays in inches, centimeters, and millimeters, but not in micrometers. Since the smallest unit of measurement on a ruler limits accuracy, it might not be the best instrument for tiny things; however, it is adaptable and can be used to measure steps, depth, and diameters both inside and outside. This study aimed to measure the thickness of a hair strand without using any conventional method, but by using a steel ruler. This research investigated comprehension of laboratory experiments and the enhancement of scientific process skills among BS Biology students taking Biophysics course. 91 students participated in the survey using a 5-point Likert Scale, ranging from "No Understanding" (0) to "Complete Understanding" (4). Findings showed that 100% of students demonstrated strong comprehension of the lab's objectives and concepts, while 85.7% reported a strong grasp of the procedures. One student (1.1%) indicated minimal comprehension of the concepts prior to the lab. Additionally, 94.5% reported that laboratory experiments greatly enhanced their comprehension of concepts. Students dedicated 30 minutes to discussing the lab afterward, and 91.2% invested 1 hour in preparing their lab reports. Moreover, participants regularly performed important laboratory tasks, including preparing materials, organizing experiments, demonstrating the activity design, and adjusting to conditions during laboratory tasks. The statistically significant results for both Q3 and Q5 support the conclusion that the developed laboratory activities fostered strong student engagement and conceptual understanding, aligning with best practices in active, inquiry-based science education.