While the ultimate decomposition achieved in ceramics is melting, many materials change their physical form in other ways prior to melting when they reach certain temperatures (i.e. the loss of crystal water, burning away of organics). Some materials go through multiple decompositional changes, each having its own chemistry.
Enter the temperature or range and a label for the event, for example:
245C: water of crystallization driven off
In ceramic manufacture, knowing about the how and when materials decompose during firing is important in production troubleshooting and optimization
Test conducted primarily on materials use to make bodies or glazes.