Analysis and Prediction of Question Topic Popularity in Community Q&A Sites: A Case Study of Quora

Abstract

In the past few years, Quora a community-driven social platform for question and answering, has grown exponentially from a small community of users into one of the largest and reliable source of Q&A on the Internet. Quora has a built-in social structure integrated to its backbone; users can follow each other, follow question, topics etc. Apart from the social connections that Quora provides, it has developed a knowledge base nicely organized via hierarchy and relatedness of topics. In this paper, we consider a massive dataset of more than four years and analyze the dynamics of topical growth over time; how various factors affect the popularity of a topic or its acceptance in Q&A community. We also propose a regression model to predict the popularity of the topics and discuss the important discriminating features. We achieve a high prediction accuracy (correlation coefficient ~0.773) with low root mean square error (~1.065). We further categorize thetopics into a few broad classes by implementing a simple Latent Dirichlet Allocation (LDA) model on the question texts associated with the topics. In comparison to the data sample with no categorization, this stratification of the topics enhances the prediction accuracies for several categories. However, for certain categories there seems to a slight decrease in the accuracy values and we present an in-depth discussion analyzing the cause for the same pointing out potential ways for improvement. We believe that this thorough measurement study will have a direct application to a service like recommending trending topics in Quora.