Where Does an Interesting Expository Text Begin?

The article provides a description of the general mechanism of text-based interest formation in expository texts. It is based on the psychological research and the linguistic analysis. The authors of textbooks use various linguistic means to increase the emotiogenicity of expository texts. The interest is activated by an incongruence between one’s prediction about an event and the actual event. So, the means of interest evocation affect the psychological mechanism of probabilistic forecasting. They also overcome the contextual predictability of expository text while deploying it. For instance, there are means aimed at overcoming the predictability of communicative context (e. g., unusual introduction) or the semantic context (e. g., contextualization, dialogizing). The analysis allows to claim that the contextual predictability of the interesting expository text is overcome not due to the message of unexpected, interesting information, but due to presentations of the speech subject that are unexpected for the addressee (e. g., challenging exposition). An interesting expository text should be coherent, because the formal, content and pragmatic coherence is the key to its successful understanding by students. Therefore, the means of interest evocation should not destroy the coherence of the completed expository text. They must be communicative and thematically relevant, otherwise the emotiogenic potential of the text will significantly decrease.