Persuasive strategy implementation choices and their effectiveness: towards personalised persuasive systems

Persuasive systems motivate behaviour change using persuasive strategies (PS) which are often implemented in various ways. However, whether or not the effectiveness of PS varies depending on implementation choices is yet to be investigated via an empirical study. We conduct a large-scale study of 568 participants to investigate if and how individuals at different Stages of Change (SoC) respond to different implementations of each strategy in the same system. We also explore why the implementations motivate behaviour change using ARCS motivation model. Our results show that people's SoC plays a significant role in the perceived effectiveness of different implementations of the same strategy and that the implementations motivate for different reasons. For instance, people at the precontemplation stage are motivated by reward strategy implemented as badges because it increases their Confidence, while people in the preparation stage prefer reward implemented as points to build their Confidence. Our work links SoC theory with motivation theory and Persuasive Systems Design (PSD) model to offer practical guidelines for tailoring PS implementations to individuals to motivate behaviour change.