New York University, 545 First Avenue Greenberg Hall, Room 6R., New York, NY 10016, USA.
Adv Health Sci Educ Theory Pract. 2013 Aug;18(3):439-50. doi: 10.1007/s10459-012-9382-z. Epub 2012 Aug 7.
Participant attrition may be a significant threat to the generalizability of the results of educational research studies if participants who do not persist in a study differ from those who do in ways that can affect the experimental outcomes. A multi-center trial of the efficacy of different computer-based instructional strategies gave us the opportunity to observe institutional and student factors linked to attrition from a study and the ways in which they altered the participation profile. The data is from a randomized controlled trial conducted at seven US medical schools investigating the educational impact of different instructional designs for computer-based learning modules for surgical clerks. All students undertaking their surgical clerkships at the participating schools were invited participate and those that consented were asked to complete five study measures during their surgery clerkship. Variations in study attrition rates were explored by institution and by participants' self-regulation, self-efficacy, perception of task value, and mastery goal orientation measured on entry to the study. Of the 1,363 invited participants 995 (73 %) consented to participate and provided baseline data. There was a significant drop in the rate of participation at each of the five study milestones with 902 (94 %) completing at least one of two module post-test, 799 (61 %) both module post-tests, 539 (36 %) the mid-rotation evaluation and 252 (25 %) the final evaluation. Attrition varied between institutions on survival analysis (p < 0.001). Small but statistically significant differences in self-regulation (p = 0.01), self-efficacy (p = 0.02) and task value (p = 0.04) were observed but not in mastery or performance goal orientation measures (p = NS). Study attrition was correlated with lower achievement on the National Board of Medical Examiners subject exam. The results of education trials should be interpreted with the understanding that students who persist may be somewhat more self-regulated, self-efficacious and higher achievers than their peers who drop out and as such do not represent the class as a whole.
参与者流失可能对教育研究结果的推广性构成重大威胁，如果不坚持研究的参与者与坚持研究的参与者在可能影响实验结果的方面存在差异。一项关于不同基于计算机的教学策略效果的多中心试验使我们有机会观察到与研究中流失相关的机构和学生因素，以及它们如何改变参与状况。该数据来自在美国七所医学院进行的一项随机对照试验，该试验调查了不同基于计算机的学习模块的教学设计对外科实习医生产生的教育影响。所有在参与学校从事外科实习的学生都被邀请参加，那些同意参加的学生被要求在外科实习期间完成五项研究措施。通过机构和参与者的自我调节、自我效能感、任务价值感和掌握目标取向的变化来探索研究流失率的差异，这些变量在进入研究时进行了测量。在 1363 名受邀参与者中，有 995 名（73%）同意参与并提供了基线数据。在五项研究里程碑中的每一项都有显著的参与率下降，其中 902 名（94%）至少完成了两个模块后测中的一个，799 名（61%）完成了两个模块后测，539 名（36%）完成了中期旋转评估，252 名（25%）完成了最终评估。在生存分析中，机构之间的流失情况存在显著差异（p<0.001）。自我调节（p=0.01）、自我效能感（p=0.02）和任务价值感（p=0.04）方面存在小但具有统计学意义的差异，但在掌握或绩效目标取向方面没有差异（p=NS）。研究流失与国家医师考试科目的成绩较低相关。在解释教育试验结果时，应认识到坚持研究的学生可能比退出研究的同龄人更具自我调节、自我效能感和更高的成就，因此他们不能代表整个班级。
