Adding sensor-free intention-based affective support to an Intelligent Tutoring System.

•A sensor-free affect-aware Intelligent Tutoring System (ITS) is presented.•The ITS is able to adapt feedback to positively affect pleasure, arousal or dominance.•The system does not use a specific emotion detection system during operation.•Results show that the level of scaffolding influences the subject’s affective state.•An experiment in a real educational setting led to statistically significant results.