13. The computer program product as claimed in claim 9 , wherein the topical recommendations are associated with different topics.
9. A computer program product stored on a non-transitory computer-readable medium that when executed by a processor, performs a method of providing a structured topic drift for a displayed set of user comments on an article, comprising: determining an ordered sequence of topical recommendations based on one or more properties of the displayed set of user comments and user characteristics using a sequential recommendation model; sampling one or more user comments for a plurality of the topical recommendations in the ordered sequence to produce a set of one or more user comments; appending, one by one, the one or more user comments for each of the topical recommendations to bottom of the displayed set of user comments; and updating the sequential recommendation model based on a user response to the one or more user comments for each of the topical recommendations; determining a second ordered sequence of topical recommendations using the sequential recommendation model; sampling one or more user comments for a plurality of the topical recommendations in the second ordered sequence to produce a second set of one or more user comments; and appending, one by one, the second set of one or more user comments for each of the topical recommendations to bottom of the displayed set of user comments.