“Run Forrest Run!”: Measuring the Impact of App-Enabled Performance and Social Feedback on Running Performance

Exercise tracking apps offer a novel and powerful channel to deliver behavioral interventions at a massive scale. As thousands of fitness tracking solutions emerge, the lack of systematic research quantifying their effectiveness on exercise outcomes becomes more prominent. Drawing on the motivation literature, this paper elucidates the effects of app-enabled motivation on fitness improvement. Specifically, this study examines the two most common forms of feedback available to users of exercise tracking apps, namely performance feedback and social feedback. The results of our field experiment reveal strong evidence that performance feedback and social feedback motivate fitness improvement. Furthermore, whereas the effect of social feedback diminishes over time, the effect of performance feedback remains resilient. There theoretical and practical implications of the findings are discussed

Falling from Digital Grace: Participation in Online Software Contests Following Loss of Status

We focus on the effects of status loss on decisions to participate in subsequent contests in online coding platform. We advance the relevant literature in several ways. First, by considering the effects of status loss on resource expenditure, we depart from the prior status literature, which has predominantly looked at performance implications of the status loss. Second, because of the voluntary nature of online contests, we demonstrate how the effects of status loss manifest when permanent exit or abstention is possible. This aspect marks another departure from situations common to the prior work, wherein work demands persist regardless of status changes. Lastly, recognizing that status changes may be endogenous to one\u27s past resource expenditure, we study exogenous variation in status, exploiting a natural experiment wherein status assignments were adjusted overnight by the platform operator, in a manner completely independent of individuals\u27 prior activities, resulting in sudden loss of statu

The Effects of Digitally Delivered Nudges in a Corporate Wellness Program

We investigate how two digitally delivered nudges, namely light social support (nonverbal cues such as kudos or likes) and motivational messaging, affect employees’ self-reported physical activity in an online, corporate wellness program. Within this unique field setting, using data from several years, we found evidence that both types of nudges provide benefits beyond the effect of cash incentives. However, the effects vary by individual, depending on whether the employee is actively engaging in physical activity, and by time, depending on how long the employee has been in the wellness program. We found light social support to be less effective over time, while motivational messages were found to be more effective with the duration in the program and generally more effective for physically inactive users. Our findings have implications for the design of wellness systems, suggesting different approaches depending on an employee’s current activity level and tenure in the progra

Robust estimation of bacterial cell count from optical density

Optical density (OD) is widely used to estimate the density of cells in liquid culture, but cannot be compared between instruments without a standardized calibration protocol and is challenging to relate to actual cell count. We address this with an interlaboratory study comparing three simple, low-cost, and highly accessible OD calibration protocols across 244 laboratories, applied to eight strains of constitutive GFP-expressing E. coli. Based on our results, we recommend calibrating OD to estimated cell count using serial dilution of silica microspheres, which produces highly precise calibration (95.5% of residuals <1.2-fold), is easily assessed for quality control, also assesses instrument effective linear range, and can be combined with fluorescence calibration to obtain units of Molecules of Equivalent Fluorescein (MEFL) per cell, allowing direct comparison and data fusion with flow cytometry measurements: in our study, fluorescence per cell measurements showed only a 1.07-fold mean difference between plate reader and flow cytometry data

Essays on Online-Offline Interactions

University of Minnesota Ph.D. dissertation. July 2020. Major: Business Administration. Advisors: Yuqing Ren, Gordon Burtch. 1 computer file (PDF); xiii, 169 pages.As communication, consumption of goods and services, and other aspects of our lives become increasingly digitized, it is important to understand how we as individuals balance the virtual world with the physical. In this thesis, I examine how online and offline interactions complement or substitute each other in two different settings. In the first chapter(essay), I empirically evaluate the impact of the introduction of a new online service, app-enabled ride-hailing, on an offline transportation market incumbent, public transit. I focus on public transit in the United States and the impact of Uber and Lyft's entry on its monthly utilization. City and agency-level factors that moderate this impact are also explored to offer guidance for transit planners as well as ride-hailing agencies to optimize the interactions between the two forms of services. In the second chapter, I explore the influence of offline face-to-face interactions on online activities in a large scale hybrid community. Using a Facebook foodie group as the context of the study, I examine how the occurrence of meetups and their attendance influences subsequent activities of the group and its individual members. Effective meetup conductance and other community administrative implications for managers are provided to help improve online community health

Run Forrest Run!: Measuring the Impact of App-Enabled Social and Performance Feedback on Running Performance

Exercise tracking apps are a novel, scalable, and affordable tool for delivering personalized behavioral interventions. While thousands of fitness tracking solutions emerge in the market, there is a lack of systematic research that quantify their effecti

The Influence of Status on Evaluations: Evidence from Online Coding Contests

In many instances, online contest platforms rely on contestants to ensure submission quality. This scalable evaluation mechanism offers a collective benefit. However, contestants may also leverage it to achieve personal, competitive benefits. Our study examines this tension from a status-theoretic perspective, suggesting that the conflict between competitive and collective benefits, and the net implication for evaluation efficacy, is influenced by contestants’ status. On the one hand, contestants of lower status may be viewed as less skilled and hence more likely to make mistakes. Therefore, low-status contestants may attract more evaluations if said evaluations are driven predominantly by an interest in collective benefits. On the other hand, if evaluations are driven largely by an interest in personal, competitive benefits, a low-status contestant makes for a less attractive target and hence may attract fewer evaluations. We empirically test these competing possibilities using a dataset of coding contests from Codeforces. The platform allows contestants to assess others’ submissions and improve evaluations (a collective benefit) by devising test cases (hacks) in addition to those defined by the contest organizer. If a submission is successfully hacked, the hacker earns additional points, and the target submission is eliminated from the contest (a competitive benefit). We begin by providing qualitative evidence based on semi-structured interviews conducted with contestants spanning the status spectrum at Codeforces. Next, we present quantitative evidence exploiting a structural change at Codeforces wherein many contestants experienced an arbitrary status reduction unrelated to their performance because of sudden changes to the platform’s color-coding system around contestant ratings. We show that status-loser contestants received systematically more evaluations from other contestants, absent changes in their short-run submission quality. Finally, we show that the excess evaluations allocated toward affected contestants were less effective, indicating status-driven evaluations as potentially less efficacious. We discuss the implications of our findings for managing evaluation processes in online contests

The Effects of Digitally Delivered Nudges in a Corporate Wellness Program

We investigate how two digitally delivered nudges, namely light social support (non-verbal cues such as kudos or likes) and motivational messaging, affect employees’ self-reported physical activity in an online, corporate wellness program. Within this unique field setting with data over several years, we find evidence that both types of nudges provide benefits beyond the effect of cash incentives. However, the effects vary by individuals, depending on whether the employee is active in exercising, and by time, depending on how long the employee has been in the wellness program. While light social support is found to be less effective over time, motivational messages are more effective with the duration in the program and generally more effective for inactive users. Our findings have implications for the design of wellness systems, suggesting different approaches depending on an employee’s current activity level and tenure with the program