Learners entering higher education may learn specialized vocabulary of new disciplines in their second language (L2) with or without support from their first language (L1). However, these learners cannot rely on an established conceptual representation in L1 when learning L2 specialized vocabulary. The effects of learning a new concept in L1 prior to learning and testing the same concept in L2 are yet unclear. The present study compared the effectiveness of L1-mediation and L2-repetition word learning methods randomly assigned to 75 bilingual adults. Participants learned subject-specific specialized vocabulary through reading a series of definition sentences in two learning episodes a week apart. The L1L2 group (N = 31) first learned L1 words on Day 1 and then their L2 translation equivalents on Day 2, while the L2L2 group (N = 44) learned the words in L2 on both days. In each learning session, participants provided self-ratings on their confidence in acquiring word meaning after reading each sentence and completed a word meaning recognition test afterward. Results using linear mixed-effects modeling showed that L1-mediation learning may ease the start of L2 word learning as shown in higher confidence ratings and less reading time, leading to a faster establishment of high-quality conceptual representations. In contrast, L2-repetition learning may strengthen lexical representations and L2-concept connections through increased exposure to L2 words. However, the two learning methods produced comparable results on L2 meaning recognition, so flexible adoption of the learning methods according to the learning goal is suggested.

进入高等教育的学习者可以在有或没有第一语言 (L1) 的支持下，用他们的第二语言 (L2) 学习新学科的专业词汇。然而，这些学习者在学习 L2 专业词汇时不能依赖 L1 中已建立的概念表示。在 L2 中学习和测试相同概念之前先在 L1 中学习一个新概念的效果尚不清楚。本研究比较了随机分配给 75 名双语成年人的 L1 中介和 L2 重复单词学习方法的有效性。参与者通过在每周两次的学习集中阅读一系列定义句子来学习特定学科的专业词汇。L1L2 组（N= 31) 在第 1 天首先学习 L1 单词，然后在第 2 天学习它们的 L2 翻译对等词，而 L2L2 组 ( N= 44) 这两天都学会了 L2 的单词。在每个学习环节中，参与者在阅读每个句子后对他们获得词义的信心进行自我评价，并在之后完成词义识别测试。使用线性混合效应模型的结果表明，L1 中介学习可以简化 L2 单词学习的开始，如更高的置信度和更少的阅读时间所示，从而更快地建立高质量的概念表示。相比之下，L2 重复学习可以通过增加对 L2 单词的接触来加强词汇表示和 L2 概念连接。然而，两种学习方法在 L2 意义识别方面产生了可比的结果，因此建议根据学习目标灵活采用学习方法。