The objectives of this research were as follows: 1) To develop the online computer lessons using self-directed learning on Computing Science for Grade 8 students, 2) to evaluate the content’s quality of the online lessons using self-directed learning on computational science for Grade 8 students, and 3) to evaluate the quality of the techniques and methodology of the online lessons using self-directed learning on computational science for Grade 8 students. The sample group used in this research were 3 experts on the content, and 3 experts on the techniques and methodology which were selected by purposive sampling technique. The research tools were the learning plan, the online lessons, the content’s quality assessment forms, and the techniques and methodology quality assessment forms. The data were analyzed by using mean and standard deviation.

The results of this research found that: 1) The online lessons using self-directed learning on computational science for Grade 8 students consisted of 3 units which were algorithm design, fundamentals of Python programming, and computer system, 2) the developed online lessons using self-directed learning had the quality of the content at the highest level (= 4.78, S.D. = 0.13), and 3) the developed online lessons using self-directed learning had the quality of the technique and methodology at a high level = 4.69, S.D. = 0.25).