Purpose: Idea density has been shown to influence comprehension time for text in various populations. This study aims to explore the influence of spoken idea density on attainment in young, healthy subjects using demographic characteristics. Methods: Students watched two online lectures and answered 10 multiple choice questions on them. Students received one more idea dense (MID) and one less idea dense (LID) lecture on two different subjects. Results: Seventy-five students completed the study achieving a higher median score after a less idea-dense lecture (LID ¼ 7(3), MID ¼ 6(3), p ¼ 0.04). Artificial neural network models revealed the first language as the main predictor of exam performance. The odds ratio (OR) of obtaining !70% after a more idea-dense lecture was six-time higher for the first language versus second language English speakers (OR ¼ 5.963, 95% CI 1.080-32.911, p ¼ 0.041). The odds ratio was not significant when receiving a less dense lecture (OR ¼ 2.298, 95% CI 0.635-8.315, p ¼ 0.205). Second-language speakers benefited from receiving a lower idea density, achieving a 10.8% score increase from high to low density, versus a 3.2% increase obtained by first language speakers. Conclusions: The propositional idea density of lectures directly influences students' comprehension, and disproportionately for second language speakers; revealing the possibility of reduced spoken idea density in levelling the attainment differential between first and second language speakers. KEYWORDSIdea density; concept density; attainment differential; international students; psycholinguistics 'The black cat sat on the mat' Idea density ¼ 5 ideas Ä 7 words ¼ 0.71 'There is a cat, which is black, and it is sitting on the mat' Idea density ¼ 5 ideas Ä 14 words ¼ 0.36

No abstract