Abstract
The chapter focuses on off-line communication using (not only) mobile devices where absence of direct communication increase the risk of misunderstanding and loss of time. Two principles that can lower this danger, the principle of charity and the principle of scaffolding, are presented first separately, and then in mutual relationship.
The aim of this chapter is to show that charity and scaffolding are two (connected) stages of help to pupils. If the teacher applies the principle of charity, it enables him/her to understand pupils and/or discover their problems.
Having detected the learners' misconceptions or problematic parts, he/she will be able to follow the pupils' thinking process and with the help of scaffolding advance the pupils' knowledge to a higher level. All the presented theoretical constructs are illustrated by examples from an on-line mathematical course for secondary pupils.
The role of technological devices in developing the quality of pupils' participation in the course is documented.