During the solution process, the student may need some help. The first available help is the guidance, which provides an initial idea on how to start. The guidance is a static tip and remains the same throughout the solution process. A dynamic help is provided by the a hint that refers to the last step that was typed by the student. The hint provides focused help either on what was wrong if the line was incorrect, or a tip on how to continue from this point if the typed line was correct.
The instruction experience of the authors has played a key role in developing an intelligent software, that can anticipate and detect common mistakes made by students and provide help when needed.
When the student makes a mistake the hint tells what it wrong.