AbstractThis study aims to develop a concrete model, the Fountain of Phase model, for the concept
of matters and determine the usability of the FOP model. The design of this study is a
development study based on the ADDIE model. A need analysis was administered to
fourteen (14) chemistry teachers across PPD Muallim, Perak, to assess the need for using
the concrete model as a teaching aid in science and chemistry education. Two validated
instruments used in this study are the model’s validity questionnaire (MVQ) and the
model’s usability questionnaire (MUQ). The MUQ was adapted from the questionnaire
Usefulness, Satisfaction, and Ease of Use (USE) by Lund in 2001. The model was
evaluated by five (5) experts from Universiti Pendidikan Sultan Idris (UPSI), including
subject matter experts, lecturers in the field of chemical education, and lecturers with at
least three (3) years of experience in teaching aid development. The FOP model had
obtained a 0.99 Content Validity Index (CVI).....