The danger of conflating level-specific effects of control variables when primary interest lies in level-2 effects

In the multilevel modelling literature, methodologists widely acknowledge that a level-1 variable can have distinct within-cluster and between-cluster effects, and that failing to disaggregate these can yield a slope estimate that is an uninterpretable, conflated blend of the two. Methodologists have stated, however, that including conflated slopes of level-1 variables in a model is not problematic if substantive interest lies only in effects of level-2 predictors. Researchers commonly follow this advice and use methods that do not disaggregate effects of level-1 control variables (e.g., grand mean centering) when examining effects of level-2 predictors. The primary purpose of this paper is to show that this is a dangerous practice. When level-specific effects of level-1 variables differ, failing to disaggregate them can severely bias estimation of level-2 predictor slopes. We show mathematically why this is the case and highlight factors that can exacerbate such bias. We corroborate these findings with simulations and present an empirical example, showing how such distortions can severely alter substantive conclusions. We ultimately recommend that simply including the cluster mean of the level-1 variable as a control will alleviate the problem.     

Self-protection and growth as the motivational force behind majority group members' cultural adaptation and discrimination: A parallel mediation model via intergroup contact and threat

What motivates majority group members to adapt to or reject cultural diversity? Considering the relevance of personal values on our attitudes and behaviours, we inspected how self-protection and growth predict levels of discriminatory behavioural and cultural adaptation intentions towards migrants via intergroup contact and perceived intergroup threats, simultaneously (i.e., parallel mediation). Specifically, positive contact between groups is known for reducing prejudice through diminishing perceived intergroup threats. Yet current research emphasises the role of individual differences in this interplay while proposing a parallel relationship between perceived intergroup threats and contact. Also by inspecting cultural adaptation and discriminatory behavioural intentions, the present study examined more proximal indicators of real-world intergroup behaviours than explored in past research. Using data from 304 US Americans, structural equation modelling indicated a good fit for a parallel mediation model with growth relating positively to cultural adaptation intentions and negatively to discriminatory behavioural intentions through being positively associated with intergroup contact and negatively with perceived intergroup threats, simultaneously. The reverse was found for self-protection. These findings stress that personal values constitute a relevant individual difference in the contact/threats-outcome relationship, providing a motivational explanation for majority group members' experience of cultural diversity in their own country.     

A comparison of teaching tacts with and without background stimuli on acquisition and generality

We evaluated whether teaching tacts of images with or without backgrounds would affect acquisition during teaching and generality across untaught targets with four children diagnosed with autism spectrum disorder. Including backgrounds could slow acquisition but bolster generality across other media containing backgrounds, whereas removing backgrounds may improve acquisition but result in poorer generality. Overall, acquisition rates were similar across conditions for three children, although one child displayed consistently slower acquisition during the background condition. We rarely observed generality to untaught targets when programming extinction, but embedding differential reinforcement or teaching additional images with backgrounds led to equally successful outcomes irrespective of initial teaching conditions. Teaching with or without backgrounds may result in marginal differences in acquisition of teaching and untaught targets, especially when arranging supplemental procedures during tests for generality. We discuss the importance of intrasubject replication, considerations when testing for generality, and implications for practice.     

A focus group study on the potential of autonomous vehicles as a viable transportation option: Perspectives from people with disabilities and public transit agencies

Autonomous vehicle (AV) technology is becoming one of the most promising alternatives to improve mobility for people with disabilities. Nevertheless, how people with disabilities perceive AV as transportation services has not been explored. Also, limited information exists about how public transit agencies comprehend and perceive autonomous vehicle transportation (AVT) services. This study discusses mobility issues for people with disabilities and explores the potential of AVT to serve that population, particularly those with visual impairments or physical disabilities. Researchers conducted six focus groups comprising people with disabilities (N = 23) and public transit service experts (N = 10) in Austin, Texas and Houston, Texas. Each session was audio-recorded and analyzed using conventional content analysis. This study identified people with disabilities’ mobility issues related to: (1) current transit services (including fixed-route and paratransit services) and (2) the quality of neighborhood built environments. Both people with disabilities and transit experts expected that AVT could mitigate current mobility issues, especially in improved built environments. However, participants with disabilities also expressed concerns and anxieties regarding AVT. Transit experts agreed that more targeted strategies would be needed to overcome possible barriers to AVT for people with disabilities. This study provides insights on shaping AVT strategies and policies relevant to improving mobility for people with disabilities.     

Do looks constitute our perceptual evidence?

Many philosophers take experience to be an essential aspect of perceptual justification. I argue against a specific variety of such an experientialist view, namely, the Looks View of perceptual justification, according to which our visual beliefs are mediately justified by beliefs about the way things look. I describe three types of cases that put pressure on the idea that perceptual justification is always related to looks‐related reasons: unsophisticated cognizers, multimodal identification, and amodal completion. I then provide a tentative diagnosis of what goes wrong in the Looks View: it ascribes a specific epistemic role to beliefs about looks that is actually fulfilled by subpersonal perceptual processes.     

视觉空间工作记忆组间差异的神经机制

为考察视觉空间工作记忆（working memory, WM）维持和操作的组间差异及其神经机制,本研究记录了高、低WM组完成延迟再认（维持）任务和心理旋转（操作）任务时的行为和事件相关电位数据。结果发现,在操作任务中,高WM组比低WM组的反应时显著更短;高WM组的中前额叶慢波显著更正、双侧后顶区慢波显著更负,并且两者的波幅显著负相关。在维持任务中,两组被试的反应时无显著差异;高WM组的中前额叶慢波显著更正。结果表明,高WM组的执行注意能力可能更强,能通过有效调节和分配加工资源来表征视觉信息。     

青少年的同伴选择与同伴影响：基于学业投入与学业成就的纵向社会网络分析

以756名中学生为研究对象,对学业投入、学业成就、同伴团体进行追踪测量,探讨青少年同伴团体的学业投入及学业成就是否存在同伴选择与同伴影响效应。结果表明：（1）在1年的追踪时间中,青少年学业投入的发展呈下降趋势,初始水平与下降速度负相关,学业成就的发展呈上升趋势,初始水平与上升速度无显著相关;（2）学业投入与学业成就存在同伴选择效应,青少年倾向选择与自己学业投入及学业成就相似的个体构建同伴团体;（3）青少年的学业投入及学业成就与同伴逐渐趋近相似,即同伴影响效应显著。     

领悟社会支持在老年人的居住地情感认同和控制感之间的中介作用：一个纵向模型

本研究以281名老年人为研究对象,探讨了城市变迁中的老年人居住地情感认同、领悟社会支持和控制感的关系。研究使用居住地情感认同问卷、领悟社会支持问卷和控制感问卷为研究工具,采用每次间隔6个月,共3次的纵向追踪设计。结果发现：老年人的居住地情感认同可以正向预测领悟社会支持,老年人的领悟社会支持可以正向预测控制感,老年人的领悟社会支持在居住地情感认同和控制感之间起纵向中介作用。本研究结果揭示了城市老年居民的居住地情感认同对控制感的影响机制,也对提升城市老年居民的控制感具有一定的实践意义。     

社会认同理论视野下的社会认同威胁

社会认同威胁是指,在社会比较的情况下,由于群体地位的差异,某一群体的个体在认知、情感上,对自我、所属群体身份的不承认,而产生的一种心理上的疏离感和剥夺感、自卑感。社会认同威胁的结果包括3类：脱离群体、改变群体的状态、接受消极的社会认同结果。外显“社会威胁”的测量方法以问卷调查为主。测量“社会威胁”的内隐方法则以心脏血压和平均动脉血压作为测量指标。社会认同威胁的实验研究将群体分化为内群体和外群体,操纵群体地位的差异,通过模拟社会游戏来了解群体的社会认同威胁及其生理反应。未来的研究将重点关注下述问题：对社会认同威胁概念的建构、跨文化研究及其内隐过程的分析     

Group problem-solving among teachers: A case study of how to improve a colleague’s teaching

A case study of six teachers cooperating to improve a teacher’s teaching showed the dynamics of the group problem-solving process. An analysis of their verbal interactions showed the importance of shared understanding to successful group problem solving. The cooperative group structure helped members resolve cognitive conflicts and build group understanding. During this process, the members’ past teaching experiences and knowledge contributed to their conceptualization of the teacher’s teaching problems and their proposed solutions to improve the teacher’s teaching. Tsz Cheung Lam graduated from the Department of Educational Psychology at the Chinese University of Hong Kong in 2004 and obtained his Master of Education degree. His research interests lie primarily on cooperative learning and problem solving. As a primary school teacher in practice, he is now studying part-time for another master degree in data science at the Department of Statistics of the Chinese University of Hong Kong.