Get sleep or get stumped: sleep behaviour in elite South African cricket players during competition

ABSTRACT

Despite evidence supporting the positive affect sleep has on sport performance, there is limited application of sleep research in cricket. This study investigated the sleep behaviours of 26 elite South African cricket players (28.6 ± 4.0 years) during home and away competition. Players completed an altered version of the Core Consensus Sleep Diary every morning post-travel, pre-match and post-match. Linear mixed model regression was used to compare differences in sleep between time-periods, venues and formats. Spearman’s correlations (r_s) assessed the relationship of match performance and sleep. Post-match total sleep time (06:31 ± 01:09) was significantly (p < 0.05) shorter compared to post-travel (07:53 ± 01:07; g = 1.19) and pre-match (08:43 ± 01:03; g = 1.98). Post-travel sleep onset latency and sleep efficiency were significantly shorter (?20; g = 1.35) and higher (+10.4%; g = 0.74) at home than away respectively. Longer sleep onset latencies and shorter total sleep times were significantly associated with poorer One-Day International (r_s = ?0.57) and Test (r_s = 0.59) batting performances respectively. The poor post-match sleep behaviour, and the sleep and performance correlations, provide motive for future interventions to focus on recovery and the use of sleep monitoring as a competitive advantage.     

Do Search Algorithms Endanger Democracy? An Experimental Investigation of Algorithm Effects on Political Polarization

ABSTRACT

This study examines algorithm effects on user opinion, utilizing a real-world recommender algorithm of a highly popular video-sharing platform, YouTube. We experimentally manipulate user search/watch history by our custom programming. A controlled laboratory experiment is then conducted to examine whether exposure to algorithmically recommended content reinforces and polarizes political opinions. Results suggest that political self-reinforcement, as indicated by the political emotion-ideology alignment, and affective polarization are heightened by political videos – selected by the YouTube recommender algorithm – based on participants’ own search preferences. Suggestions for how to reduce algorithm-induced political polarization and implications of algorithmic personalization for democracy are discussed.     

Contemporary Perspectives on the Meaning,Roles, and Implications of Chance in Evolution

Science & Education -     

Impact of Both Local Item Dependencies and Cut‐Point Locations on Examinee Classifications

Performance assessments, scenario‐based tasks, and other groups of items carry a risk of violating the local item independence assumption made by unidimensional item response theory (IRT) models. Previous studies have identified negative impacts of ignoring such violations, most notably inflated reliability estimates. Still, the influence of this violation on examinee ability estimates has been comparatively neglected. It is known that such item dependencies cause low‐ability examinees to have their scores overestimated and high‐ability examinees' scores underestimated. However, the impact of these biases on examinee classification decisions has been little examined. In addition, because the influence of these dependencies varies along the underlying ability continuum, whether or not the location of the cut‐point is important in regard to correct classifications remains unanswered. This simulation study demonstrates that the strength of item dependencies and the location of an examination systems’ cut‐points both influence the accuracy (i.e., the sensitivity and specificity) of examinee classifications. Practical implications of these results are discussed in terms of false positive and false negative classifications of test takers.     

Commentary: the first 20 years of Soccer and Society

Soccer and Society was the first, and remains the only, international academic journal that is focused on a single sport. In anticipation of the vicennial volume, I offer here a snapshot of this journal’s content over its first 20 years. This commentary is part-audit and part-personal observation of the main themes, countries, tournaments, leagues and clubs that have featured, and on the gender of those who have written for the journal. The aim here is to offer a timely reflection on those elements within football that have been well served and those which have been under-represented. After briefly outlining the purpose of academic journals, I present the findings of this audit and conclude with some questions on the next 20 years.     

Chinese Postgraduate Choices When Considering a UK Business and Management Programme

This research investigated Chinese students' decision making processes for enrolling on a postgraduate taught business and management programme in a UK university, based on structured interviews, followed by a survey of just over 450 respondents. The validity and reliability of the research instrument were assessed prior to issuing the survey. Convenience sampling was used to collect questionnaires from Chinese students in seven universities in the Northwest of the UK, and the findings were analysed using frequency and factor analysis. The research shows that Chinese students chose a country first, a programme (Business & Management) second, a university third, and a city last; the four choices are determined by 14 factors comprising 42 variables. This study has managerial implications for UK universities' policy makers, managers and practitioners to promote their programmes in China.     

钓鱼执法，可以休矣

孙中界事件已经过去两个多月,但其影响远远没有结束,案件当中的钓鱼执法更是引发人们的热议。其实,国外也存在钓鱼执法。外国是如何看待它,如何防止它发生的呢？本期焦点,我们为大家介绍钓鱼执法的历史,著名案例,并给出我们的建议。     

The assessment of lesson plans in teacher education: a case study in assessment validity and reliability

This paper forms part of an exploration of assessment on one part‐time higher education (HE) course: an in‐service, professional qualification for teachers and trainers in the learning and skills sector which is delivered on a franchise basis across a network of further education colleges in the north of England. This paper proposes that the validity and reliability of portfolio‐based assessment, a key component of many HE programmes in addition to the course being researched here, is contestable. Analysis of the processes of compiling portfolios for assessment, through the conceptual framework of the New Literacy Studies, suggests that the ways in which portfolios are assessed and the ways in which the crucial requisites of validity and reliability are assigned to them, mask complexities and contradictions in their creation by the student. This paper argues for a new, critical analysis of portfolio production and raises a number of questions about the validity, reliability and authenticity of the assessment process that the portfolios reify.     

Family Bonding with Universities

One justification offered for legacy admissions policies at universities is that that they bind entire families to the university. Proponents maintain that these policies have a number of benefits, including increased donations from members of these families. We use a rich set of data from an anonymous selective research institution to investigate which types of family members have the most important effect upon donative behavior. We find that the effects of attendance by members of the younger generation (children, children-in-law, nieces and nephews) are greater than the effects of attendance by the older generations (parents, parents-in-law, aunts and uncles). Previous research has indicated that, in a variety of contexts, men and women differ in their altruistic behavior. However, we find that there are no statistically discernible differences between men and women in the way their donations depends on the alumni status of various types of relatives. Neither does the gender of the various types of relatives who attended the university seem to matter. Thus, for example, the impact of having a son attend the university is no different from the effect of a daughter.     

"病危"的世界奇迹

我们的星球在经过了人类这几个世纪以来的摧残,现在已经满目疮痍.自然植物被破坏,全球气候变暖,自然环境逐年恶劣,不仅如此,古代的遗迹--人类文明的见证也在走向消亡,我们该怎么做呢?是该警示的时候了--