Deconstructing gamification: evaluating the effectiveness of continuous measurement,virtual rewards,and social comparison for promoting physical activity

Game design elements are often implemented in persuasive systems aimed to promote physical activity, a process called “gamification.” Gamification is believed to motivate users to become more active, and is commonly implemented in commercial products. However, relatively few studies rigorously evaluated the effectiveness of gamification, and they yielded contradicting findings. We set out to evaluate the effectiveness of virtual rewards and social comparison—two game elements prevalent in persuasive systems. We developed a research prototype, called “StepByStep,” aimed to promote routine walking. We created different versions of StepByStep, implemented as an application on Android-based mobile devices, and compared their effectiveness in two field studies. Study 1 showed that a quantified version of the application—offering continuous measurement of walking time, a daily goal, and real-time feedback on progress toward this goal—facilitated reflection on activity and significantly increased walking time over baseline level. Study 2 showed that gamified versions offering virtual rewards and social comparison were only as effective as the quantified version. Thus, we advise designers to facilitate reflection on meaningful aspects of physical activity by developing novel ubiquitous measures. Furthermore, our findings highlight the importance of systematic comparisons between quantified and gamified elements for better understanding their motivational affordances.     

Using Taxometric Analysis to Distinguish a Small Latent Taxon From a Latent Dimension With Positively Skewed Indicators: The Case of Involuntary Defeat Syndrome.

Joining the debate on the structure of depression, S. R. H. Bearh and N. Amir (2003) analyzed college students' responses to 6 Beck Depression Inventory (BDI) items with predominantly somatic content and concluded that they identified a small latent taxon corresponding to involuntary defeat syndrome. An exact replication of these analyses yielded virtually identical taxometric results, but parallel analyses of simulated taxonic and dimensional comparison data matching the intercorrelations and skewed distributions of the BDI items showed the results to be more consistent with dimensional than with taxonic latent structure. Analyses in a clinical sample with nonskewed indicators further supported a dimensional interpretation. The authors discuss methodological strategies for conducting and interpreting taxometric analyses under the adverse conditions commonly encountered in psychopathology research, including skewed indicators and small putative taxa. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Scaled and permuted string matching

The goal of scaled permuted string matching is to find all occurrences of a pattern in a text, in all possible scales and permutations. Given a text of length n and a pattern of length m we present an O(n) algorithm.     

The latent structure of analogue depression: Should the Beck Depression Inventory be used to classify groups?

Research on depression is often conducted with analogue samples that have been divided into depressed and nondepressed groups using a cutoff score on the Beck Depression Inventory (BDI). Although the relative merits of different cut scores are frequently debated, no study has yet determined whether the use of any cut score is valid, that is, whether the latent structure of BDI depression is categorical or dimensional in analogue samples. The BDI responses of 2,260 college students were submitted to 3 taxometric procedures whose results were compared with those of simulated data sets with equivalent parameters. Analyses provided converging evidence for the dimensionality of analogue depression, arguing against the use of the BDI to classify analogue participants into groups. Analyses also illustrated the notable impact of pronounced skew on taxometric results and the value of using simulated comparison data as an interpretive aid. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Informing the continuity controversy: A taxometric analysis of depression.

Researchers and practitioners have long debated the structural nature of mental disorders. Until recently, arguments favoring categorical or dimensional conceptualizations have been based primarily on theoretical speculation and indirect empirical evidence. Within the depression literature, methodological limitations of past studies have hindered their capacity to inform this important controversy. Two studies were conducted using MAXCOV and MAMBAC, taxometric procedures expressly designed to assess the underlying structure of a psychological construct. Analyses were performed in large clinical samples with high base rates of major depression and a broad range of depressive symptom severity. Results of both studies, drawing on 3 widely used measures of depression, corroborated the dimensionality of depression. Implications for the conceptualization, investigation, and assessment of depression are discussed. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Counteractive self-control in overcoming temptation.

How do anticipated short-term costs affect the likelihood of engaging in an activity that has long-term benefits. Five studies investigated the factors that determine (a) how anticipated short-term costs elicit self-control efforts and (b) how self-control efforts eventually diminish the influence of short-term costs on behavior. The studies manipulated short-term costs (e.g., painful medical procedures) and assessed a variety of self-control strategies (e.g., self-imposed penalties for failure to undergo a test). The results show that short-term costs elicit self-control strategies for self rather than others, before rather than after behavior, when long-term benefits are important rather than unimportant and when the costs are moderate rather than extremely small or large. The results also show that the self-control efforts help people act according to their long-term interests. (PsycINFO Database Record (c) 2011 APA, all rights reserved)     

Pursuing goals with others: Group identification and motivation resulting from things done versus things left undone.

This article addresses what factors best motivate individuals to work toward shared goals. We propose that when individuals do not identify highly with a group, their contributions will mimic others': An emphasis on things done will increase their contributions toward achieving a goal, because such emphasis suggests the goal is worth pursuing. Conversely, we propose that when individuals identify highly with a group, their contributions will compensate for others': An emphasis on things left undone will increase their own contributions, because missing contributions suggest insufficient progress toward a goal they already consider worthwhile. Five studies lend support to these predictions by measuring contributions to goals centered on idea generation and helping victims of various global disasters (earthquake in Haiti, wildfires in Southern California, rioting in Kenya). (PsycINFO Database Record (c) 2011 APA, all rights reserved)     

The latent structure of posttraumatic stress disorder: A taxometric investigation of reactions to extreme stress.

Mental health professionals have debated whether posttraumatic stress disorder (PTSD) can be qualitatively distinguished from normal reactions to traumatic events. This debate has been fueled by indications that many trauma-exposed individuals evidence partial presentations of PTSD that are associated with significant impairment and help-seeking behavior. The authors examined the latent structure of PTSD in a large sample of male combat veterans. Three taxometric procedures--MAMBAC, MAXEIG, and L-Mode--were performed with 3 indicator sets drawn from a clinical interview and a self-report measure of PTSD. Results across procedures, consistency tests, and analysis of simulated comparison data all converged on a dimensional solution, suggesting that PTSD reflects the upper end of a stress-response continuum rather than a discrete clinical syndrome. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Mother's insightfulness regarding their infants' internal experience: Relations with maternal sensitivity and infant attachment.

This study examined the associations among mothers' insightfulness into their infants' internal experience, mothers' sensitivity to their infants' signals, and infants' security of attachment to their mothers. The insightfulness of 129 mothers of 12-month-old infants was assessed by showing mothers 3 videotaped segments of observations of their infants and themselves and interviewing them regarding their infants' and their own thoughts and feelings. Interviews were classified into 1 insightful and 3 noninsightful categories. Mothers' sensitivity was assessed during play sessions at home and at the laboratory, and infant-mother attachment was assessed with the Strange Situation. Mothers classified as positively insightful were rated as more sensitive and were more likely to have securely attached children than were mothers not classified as positively insightful. Insightfulness also accounted for variance in attachment beyond the variance explained by maternal sensitivity. These findings add an important dimension to research on caregiving, suggesting that mothers' seeking of explanations for the motives underlying their infants' behavior is related to both maternal sensitivity and infant attachment. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Doping Molecular Monolayers: Effects on Electrical Transport Through Alkyl Chains on Silicon

n‐Si/C_nH_{2n + 1}/Hg junctions (n = 12, 14, 16 and 18) can be prepared with sufficient quality to assure that the transport characteristics are not anymore dominated by defects in the molecular monolayers. With such organic monolayers we can, using electron, UV and X‐ray irradiation, alter the charge transport through the molecular junctions on n‐ as well as on p‐type Si. Remarkably, the quality of the self‐assembled molecular monolayers following irradiation remains sufficiently high to provide the same very good protection of Si from oxidation in ambient atmosphere as provided by the pristine films. Combining spectroscopic (UV photoemission spectroscopy (UPS), X‐ray photoelectron spectroscopy (XPS), Auger, near edge‐X‐ray absorption fine structure (NEXAFS)) and electrical transport measurements, we show that irradiation induces defects in the alkyl films, most likely C?C bonds and C? C crosslinks, and that the density of defects can be controlled by irradiation dose. These altered intra‐ and intermolecular bonds introduce new electronic states in the highest occupied molecular orbital (HOMO)–lowest unoccupied molecular orbital (LUMO) gap of the alkyl chains and, in the process, dope the organic film. We demonstrate an enhancement of 1–2 orders of magnitude in current. This change is clearly distinguishable from the previous observed difference between transport through high quality and defective monolayers. A detailed analysis of the electrical transport at different temperatures shows that the dopants modify the transport mechanism from tunnelling to hopping. This study suggests a way to extend significantly the use of monolayers in molecular electronics.