Instruments
The Web pages about dissolve concept. The Web pages about dissolve concept were chosen by the
science teacher in this study and determined by the other two experts to reach consensus. The expert panel was
made up of one science educator and one science teacher who had taught science in elementary school for 12
years. At the beginning of this study, the science teacher chosen eight Web pages about dissolve concept, and
all of the experts discussed the appropriateness of the Web pages. At last, one Web page about dissolve concept
(see Figure 1) was been chosen until all the experts reached consensus.