One of the most powerful features in any Help System is Search. In my experience, more people will use the Search feature to quickly try to find answers to questions than will use the Table of Contents or Index combined.
Search has been an essential part of RoboHelp's output for years. If a searched word is contained within a topic, the topic will be shown to the user. However, it's possible to use RoboHelp Microcontent feature and allow the user to pose questions to the Search feature using full sentences. You can prepare for those questions and create short bursts of information--microcontent--and have that content appear onscreen.