Clustering all users' comments by theme is a team exercise in understanding what matters to their users.  The outcome produces a story about why the primary users do what they do, when they do it, and with whom, to achieve their goal.  The product designed from that exercise would support that story's underlying intention - the motivations of the main characters.

Method

Affinity building exercises sort a large number of ideas, opinions, or issues into themes reflecting a narrative flow of user experience.  The build process reveals patterns and relationships between ideas, leading to out-of-the-box thinking and truly creative solutions. 

The process involves brainstorming relationships between issues; naming collections with "I" statements, and then labeling multiple groups as themes.   The outcome will of identified themes will enhance the group's understanding of the components that make up an issue. 

Results

Issues organized into themes representing essential user experience issues facing the design.

Timeframe

6 hours to 3 days depending on the diversity of users and content affected by the subject of the project.  A group of 6-8, might sort as many as 2000 notes or as few as 400.  The more people working on this method, the better, so I believe in bringing in the stakeholders to see the user issues up-close at this stage.