Graded readers (GRs) are a popular language-learning resource, as they provide contextualized input adapted to any level. Still, their creation process is non-systematic and their quantity is limited. This article investigates, firstly, the progression of linguistic complexity in a series of Spanish GRs of consecutive levels, and secondly, whether literary works (LWs) targeted at specific age groups of L1 speakers exhibit a similar gradation, thus representing suitable complementary material. For this purpose, we (1) fitted two random forests on 40 complexity features computed by processing 50 GRs, 50 LWs, and 8,585 graded lexical items; (2) performed intergroup comparisons with a reference corpus through permutation tests on the four features most informative to the random forests; and (3) further explored vocabulary using distributional techniques. Our findings indicate that complexity does not progress uniformly across levels or linguistic dimensions for both GRs and LWs. Moreover, LWs only differ substantially from GRs in their lowest level. This demonstrates the importance of considering quantitative measures such as the ones presented in this study to develop balanced language teaching materials.

中文翻译：

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解构巴别塔图书馆：西班牙语分级读物和文学作品的语言复杂性分析


分级读者 （GR） 是一种流行的语言学习资源，因为它们提供适合任何级别的上下文输入。尽管如此，它们的创建过程是非系统的，数量也是有限的。本文首先研究了一系列连续级别的西班牙语 GR 中语言复杂性的进展，其次，针对 L1 使用者特定年龄组的文学作品 （LW） 是否表现出相似的等级，从而代表了合适的互补材料。为此，我们 （1） 通过处理 50 个 GRs、50 个 LWs 和 8,585 个分级词汇项目计算出的 40 个复杂性特征上拟合了两个随机森林;（2） 通过对随机森林最有用的四个特征进行排列测试，与参考语料库进行组间比较;（3） 使用分布技术进一步探索词汇。我们的研究结果表明，GR 和 LW 的复杂性在各个层次或语言维度上的进展并不统一。此外，LW 仅在最低级别上与 GR 有很大不同。这表明考虑量化措施（例如本研究中提出的措施）以开发平衡的语言教材的重要性。