Providing contingent or adaptive support (i.e., scaffolding) is effective. Yet it is unclear how it promotes students’ learning. In this mixed-methods study, we investigated to what extent the effect of contingent support for students’ learning is mediated by the extent to which students take up teachers’ support in subsequent small-group work. We define contingent support as support that contains adapted levels of teacher control or regulation based on the learner’s level of understanding. To explore the research question, we analyzed all interactions from 35 lessons of 7 secondary social studies teachers and 7 small groups of students. Logistic multilevel mediation analyses showed that the likelihood of students formulating accurate answers during small-group work was higher when students applied the teacher’s support in subsequent small-group work (as opposed to ignoring that support). However, the contingency of a teacher’s support did not affect students’ uptake or the accuracy of their answers. Additional qualitative analyses showed that students’ uptake of contingent support was sometimes hampered by untimely fading of the support. Moreover, we found that contingent support that was then gradually faded was the most effective in fostering students’ uptake of a teacher’s support.

提供临时或适应性支持（即脚手架）是有效的。尚不清楚它如何促进学生的学习。在这项混合方法研究中，我们调查了学生在随后的小组工作中接受老师支持的程度在多大程度上调节了对学生学习的临时支持的效果。我们定义或有支持作为支持，其中包含根据学习者的理解水平调整的教师控制或调节水平。为了探讨研究问题，我们分析了来自7位中学社会研究老师和7个小组学生的35课的所有互动。逻辑多层次调解分析显示，当学生在随后的小组工作中应用老师的支持时（而不是忽略这种支持），学生在小组工作中制定准确答案的可能性更高。但是，教师支持的偶然性不会影响学生的接受程度或答案的准确性。其他定性分析表明，有时由于支持的不及时消失而阻碍了学生获得临时支持。此外，