Mobile-Based Interventions For Healthy Dietary Choices

Ms Ji Eun Shin
Dr Oh Hyelim, Assistant Professor, School of Computing
Dr Atreyi Kankanhalli, Provost'S Chair Professor, School of Computing

  10 Dec 2019 Tuesday, 02:00 PM to 03:30 PM

 Executive Classroom, COM2-04-02


This thesis proposal studies mobile-based interventions for healthy dietary choices. With the proliferation of mobile apps to promote healthy diets, vast amounts of food information in recent times has altered the way people process and are influenced by such information. Pursuant to the popularity of this phenomenon, a growing corpus of academic work has been done to understand the influence of mobile-based interventions including the provision of nutrition information, social support, or dietary instructions for dietary behavior change. While most extant literature provides explanations of the effect of those interventions on the result of users' health status, these studies make little explicit reference to the theory that can explain the links among the influence of intervention, the moderating role of users' information processing, and the behavioral results. This suggests the need for more theory-based studies to understand the relationship between intervention content in mobile apps and a moderating role of users' information processing implied by theory. This thesis proposal seeks to extend the boundary of the dietary behavior literature by examining the influences of information cues with regard to two aspects: authority cue and social proof cue which derived from information processing concepts. These constitute two essays of this proposal.

The first essay, "Effects of Expert and User-Generated Reviews on Vice and Virtue Food Product Choices," examines both the effects of authority cue and social proof cue on food product choices. Provided by either other users or experts, reviews are closely correlated with consumer choice decisions. Building on the existing food and health literature that emphasizes the role of users' perceptions of food types in their food product choices, we further investigate how product reviews influence users' food product choices based on their perceived healthiness of the product in a mobile app. We use a regression discontinuity design to uncover the effects of authority cue (expert grade) and Poisson regression to analyze the effects of social proof cue (user rating) on food product choices under a given condition of an authority cue. In general, we found that while both the authority cue and social proof cue enable users to make informed choices, the information cues have more value to users when users choose healthy foods compared to indulgent foods. Because of the users' positive perceptions of the consumption process of organic food products, there may be higher review dependency on the choice of organic foods.

In the second essay, "Is Diversity of Opinion Better? The Effects of Dispersion in Mobile Word of Mouth and Healthiness Perception on Food Product Choices," we continue our exploration of the impacts of social proof cue on food product choices by focusing the roles of dispersion (degree of scatter) in social text reviews. Prior research has focused on investigating the impact of the volume and valence of ratings on sales, but little is known about how the dispersion of social text reviews matters. Building on research about the distribution of WOM, we propose that WOM dispersion, considering the influence of both opposing and diverging opinions on users' choice of food products, can have differing effects, and that there would be a moderating effect on users' primary perception of the healthiness of foods. While consumers generally prefer products that have a critical consensus within their reviews, they can be tolerant of a specific type of dispersion, i.e., a topic diversity of diverging opinions or opposite sentiment of opposing opinions. Furthermore, the effect of the dispersion on their choices can be changed at a greater level based on the underlying product attributes. To capture the divergence in opinions, we measured the semantic topic distance between vectors of texts. To capture the level of contradiction in opinions, we measured the prevailing emotions within the text of the reviews. Our preliminary findings show that a higher positive skew in the sentiment in WOM corresponds to lower subsequent choice of product, especially when a food product is perceived as a healthy product type. Moreover, a higher dispersion in the sentiment in WOM is related to the higher number of choices for a healthy perceived product type. The initial results of our study provide insights into the effect of dispersion in mobile WOM by synthesizing prior findings and show that people may process information differently because of an underlying effect of product attributes when reading WOM with a different distribution.