How can you simulate level of curiosity for a chat bot? I'd like to know more about implementing emotional intelligence.

Given I'm implementing a chat bot and I'd like to introduce the levels of curiosity to measure whether user text input is interesting or not.

High level would mean bot is asking more questions and is following the topic, lower level of curiosity makes the bot not asking any questions and changing the topics.

Less interesting content could mean the bot doesn't see any opportunity to learn something new or it doesn't understand the topic or doesn't want to talk about it, because of its low quality. 

How this possibly can be achieved? Are there any examples?
It's possible to implement a form of curiosity-driven behavior without requiring full 'emotional intelligence'. One elementary strategy would be to define some form of similarity measure on inputs.

More generally, Jurgen Schmidhuber has pioneered work on 'Artificial Curiosity/Creativity' and 'Intrinsic Motivation' and has written a number of papers on the subject:


Artificial Curiosity 
Intrinsic Motivation


Here is a video of a nice associated presentation.