Results from questionnaire on perception of the learning unit, classroom observation, and semi-structured
interview supported that students have positive attitude toward a developed learning unit. Mean scores from
questionnaire ranged from 3.91-4.24 with the highest criteria of cooperative work while the others are nearly the
same. The results from semi-structured interviews of the five volunteers’ students in experimental group also
supported the summary. Most students satisfied to use a hands-on activity to enhance experimental skills. Excerpts
from the students are as follows