Classification Consistency and Accuracy With Atypical Score Distributions

The current study aims to evaluate the performance of three non-IRT procedures (i.e., normal approximation, Livingston-Lewis, and compound multinomial) for estimating classification indices when the observed score distribution shows atypical patterns: (a) bimodality, (b) structural (i.e., systematic) bumpiness, or (c) structural zeros (i.e., no frequencies). Under a bimodal distribution, the normal approximation procedure produced substantially large bias. For a distribution with structural bumpiness, the compound multinomial procedure tended to introduce larger bias. Under a distribution with structural zeroes, the relative performance of selected estimation procedures depended on cut score location and the sample-size conditions. In general, the differences in estimation errors among the three procedures were not substantially large.     

A Web-Based Virtual Microscopy Platform for Improving Academic Performance in Histology and Pathology Laboratory Courses: A Pilot Study

Virtual microscopy (VM) has been utilized to improve students' learning experience in microscope laboratory sessions, but minimal attention has been given to determining how to use VM more effectively. The study examined the influence of VM on academic performance and teacher and student perceptions and compared laboratory test scores before and after VM incorporation. A total of 662 third-year students studying histology and 651 fourth-year students studying pathology were divided into two groups. The light microscopy (LM) group used a light microscope in 2014 and 2015, while the LM + VM group used the VM platform and a light microscope in 2016 and 2017. Four factors positively predict laboratory scores (R square, 0.323; P < 0.001): (i) the pathology course and test-enhanced learning, (ii) the VM platform and experience, (iii) medical students and lecture scores, and (iv) female students. The LM + VM group exhibited less score variability on laboratory examinations relative to their mean than the LM group. The LM + VM group was also associated with fewer failing grades (F grade; odds ratio, 0.336; P < 0.001) and higher scores (A grade; odds ratio, 2.084; P < 0.001) after controlling for sex, school, course, and lecture grades. The positive effect of the VM platform on laboratory test grades was associated with prior experience using the VM platform and was synergistic with more interim tests. Both teachers and students agreed that the VM platform enhanced laboratory learning. The incorporation of the VM platform in the context of test-enhanced learning may help more students to master microscopic laboratory content.     

Understanding the majority opinion formation process in online environments: An exploratory approach to Facebook

Majority opinions are often observed in the process of social interaction in online communities, but few studies have addressed this issue with empirical data. To identify an appropriate theoretical lens for explaining majority opinions in online environments, this study investigates the skewness statistic, which indicates how many “Likes” are skewed to major comments on a Facebook post; 3489 posts are gathered from the New York Times Facebook page for 100 days. Results show that time is not an influential factor for skewness increase, but the number of comments has a logarithmic relation to skewness increase. Regression models and Chow tests show that this relationship differs depending on topic contents, but majority opinions are significant in overall. These results suggest that the bandwagon effect due to social affordance can be a suitable mechanism for explaining majority opinion formation in an online environment and that majority opinions in online communities can be misperceived due to overestimation.     

Lessons learned and tables turned: ‘(in)security’ and media representations in the 2018 World Cup

ABSTRACT

This essay follows up on an article published in Soccer & Society prior to the 2018 World Cup in Russia. There it was argued that this edition of the World Cup served as particularly interesting for the academic field focussed on sport-mega events (SMEs) and ‘security’, because of its uniquely securitized climate. Written immediately after the 2018 World Cup, the present essay reflects upon the event’s ‘security’ and mega-event security more broadly. It revisits some ‘security-related’ episodes. Then, special attention will be given the media discourse vis-à-vis ‘hooliganism’. The essay argues that the media discourse took an unorthodox ‘turn’ with regard to English ‘hooligans’, who, compared to past events, were portrayed as being ‘in risk’ – rather than being the group generating ‘the risk’ of football-related violence and public disorder.     

Validation of a videogrammetry technique for analysing American football helmet kinematics

ABSTRACT

Professional American football games are recorded in digital video with multiple cameras, often at high resolution and high frame rates. The purpose of this study was to evaluate the accuracy of a videogrammetry technique to calculate translational and rotational helmet velocity before, during and after a helmet impact. In total, 10 football impacts were staged in a National Football League (NFL) stadium by propelling helmeted 50th percentile male crash test dummies into each other or the ground at speeds and orientations representative of concussive impacts for NFL players. The tests were recorded by experienced sports film crews to obtain video coverage and quality typically available for NFL games. A videogrammetry procedure was used to track the position and rotation of the helmet throughout the relevant time interval of the head impact. Compared with rigidly mounted retroreflective marker three dimensional (3-D) motion tracking that was concurrently collected in the experiments, videogrammetry accurately calculated changes in translational and rotational velocity of the helmet using high frame rate (two cameras at 240 Hz) video (7% and 15% error, respectively). Low frame rate (2 cameras at 60 Hz) video was adequate for calculating pre-impact translational velocity but not for calculating the translational or rotational velocity change of the helmet during impact.     

Platform War vs. Platform Synergy? A Longitudinal Analysis of Media Substitution between Personal Computers and Mobile Devices

ABSTRACT

Research on media substitution theory has examined substitutional and/or complementary relationships between new and existing media. This study focuses on the growth of mobile platforms and investigates the relationship between mobile devices and personal computers. Using Nielsen’s panel data that provide electronically recorded media usage (N = 2,396), this study analyzes yearly changes in time allocation to mobile devices and PCs at total and content-specific usage levels during mobile 4G transition. Results suggest a complementarity dynamic between mobile devices and PCs; however, the patterns were more nuanced in light of the role of individual and structural factors when determining media choice.     

Value Profiles During Middle Childhood: Developmental Processes and Social Behavior

Little is known about how children's value priorities develop over time. This study identifies children's value priority profiles and follows their development during middle childhood. Australian children (N = 609; ages 5–12 at Time 1) reported their values over 2 years. Latent Transition Analysis indicated four profiles: Social-Focus, Self-Focus, Growth-Focus and Undifferentiated. Within person development was characterized by profile stability or transfer to the Social-Focus profile. Younger children were more likely to have an Undifferentiated profile (or Self-Focus among boys) than older ones. Girls were more likely to have a Social-Focus profile or transfer to it, and less likely to have a Self- or Growth-Focus profile than boys. Social-Focus profile membership over time predicted more prosocial and less aggressive behavior.     

Identifying Liars Through Automatic Decoding of Children's Facial Expressions

This study explored whether children's (N = 158; 4- to 9 years old) nonverbal facial expressions can be used to identify when children are being deceptive. Using a computer vision program to automatically decode children's facial expressions according to the Facial Action Coding System, this study employed machine learning to determine whether facial expressions can be used to discriminate between children who concealed breaking a toy(liars) and those who did not break a toy(nonliars). Results found that, regardless of age or history of maltreatment, children's facial expressions could accurately (73%) be distinguished between liars and nonliars. Two emotions, surprise and fear, were more strongly expressed by liars than nonliars. These findings provide evidence to support the use of automatically coded facial expressions to detect children's deception.     

“Lies,damn lies and statistics”: a history of museum visits in Australasia

ABSTRACT

While a great deal of attention has been paid to museum visit data in the last few decades, very little is known about long-term trends. This article examines the distinctive history of museum visits in Australasia through a comparative study of eight key institutions from across the region. Archival research was undertaken at each institution to compile as complete as possible a data set of annual visitation from opening until present day. Any stated changes in funding, admission charges, buildings etc. were also recorded, along with comments indicating contemporary explanations for fluctuations in visitation. Sources included official documents such as annual reports and trustee minutes, as well as visitor books and attendance records. We provide an initial overview of the quantitative and contextual data we collected from the case study museums focusing on a number of key questions: How have museums in Australasia been counting and reporting visit data over the past 150 years? What does this reveal about changes over time in the perceived value of visit data and museum attitudes towards their visitors? What are the key trends in museum attendance at the local, national and regional level in Australia and New Zealand? What contemporary explanations were given for fluctuations in museum attendance and are they supported by a long-term, cross-institutional comparison of the data? The study provides insights into historical shifts in thinking about the importance of visitors, appropriate methods for recording visitation, and the value of this data. The findings are also relevant to how museums today interpret attendance figures. The ways in which visit data were included or excluded from historical narratives about the value of museums highlights the constructed nature of visitor data and raises questions about the role of visitor research in contemporary museums.