Hierarchical Re-estimation of Topic Models for Measuring Topical Diversity

A high degree of topical diversity is often considered to be an important characteristic of interesting text documents. A recent proposal for measuring topical diversity identifies three elements for assessing diversity: words, topics, and documents as collections of words. Topic models play a central role in this approach. Using standard topic models for measuring diversity of documents is suboptimal due to generality and impurity. General topics only include common information from a background corpus and are assigned to most of the documents in the collection. Impure topics contain words that are not related to the topic; impurity lowers the interpretability of topic models and impure topics are likely to get assigned to documents erroneously. We propose a hierarchical re-estimation approach for topic models to combat generality and impurity; the proposed approach operates at three levels: words, topics, and documents. Our re-estimation approach for measuring documents' topical diversity outperforms the state of the art on PubMed dataset which is commonly used for diversity experiments.Comment: Proceedings of the 39th European Conference on Information Retrieval (ECIR2017

Exploring the commercial value of social networks: enhancing consumers’ brand experience through Facebook pages

Purpose – The purpose of this paper is to understand the factors which impact upon the consumers’ willingness to utilise company Facebook pages and e-word-of mouth by proposing and testing a conceptual framework which is inspired by theories in marketing and information systems fields. The authors believe that only by applying both theories will provide a more complete understanding of the relationship between brand experience and Facebook. The research model attempts to illustrate the factors according to customers’ intrinsic and extrinsic motivations and their impact on brand experience, brand Facebook page loyalty and e-word-of-mouth (E-WOM). Design/methodology/approach – The authors adopted an online survey method for data collection. The subjects the authors used were Facebook users. The data were collected in Taiwan over spring 2011. The authors then used the structural equation model to analyse the data collected. Findings – The findings suggest that users are influenced by the technical characterises of a brand Facebook page, such as ease of use and usefulness, which might be combated by attempting to reduce customer effort when accessing Facebook pages. The authors conclude that customer effort influenced brand experience and consequently loyalty to brand Facebook pages and E-WOM. Research limitations/implications – The limitations of this study relate to the investigation of consumer perspectives in a specific geographical context and time frame. Originality/value – The study’s contributions are both theoretical and practical, as it offers new insights into brand experience attitudes in an online environment and useful insights to companies willing to market themselves on Facebook. Keywords Marketing, Facebook, Virtual community, Extrinsic motivations, Intrinsic motivations Paper type Research pape