Text simplification refers to the process of increasing the comprehensibility
of texts. Automatic text simplification models are most commonly evaluated by
experts or crowdworkers instead of the primary target groups of simplified
texts, such as persons with intellectual disabilities. We conducted an
evaluation study of text comprehensibility including participants with and
without intellectual disabilities reading unsimplified, automatically and
manually simplified German texts on a tablet computer. We explored four
different approaches to measuring comprehensibility: multiple-choice
comprehension questions, perceived difficulty ratings, response time, and
reading speed. The results revealed significant variations in these
measurements, depending on the reader group and whether the text had undergone
automatic or manual simplification. For the target group of persons with
intellectual disabilities, comprehension questions emerged as the most reliable
measure, while analyzing reading speed provided valuable insights into
participants' reading behavior.

文本简化是增加文本可理解性的过程。我们通过一个评估研究，使用智力残疾人和普通参与者阅读自动和手动简化的德语文本来探索衡量可理解性的四种不同方法，并发现这些方法在不同读者群体和文本是否经历自动或手动简化时会有显著差异。对于智力残疾人这个目标群体，理解问题是最可靠的衡量手段，而分析阅读速度则为了解参与者的阅读行为提供了有价值的见解。