“…The input to young learners reflects these complex goals. Child-directed input is multidimensional, incorporating a diverse set of communicative cues across multiple modalities, and this multidimensional input is highly variable over time and across individuals, communities and cultures Bergelson, Casillas, et al, 2019;Casillas et al, 2020;Holler & Levinson, 2019;Kosie & Lew-Williams, 2023;Piazza et al, 2021;Ryskin & Fang, 2021;Schatz et al, 2022;Suarez-Rivera et al, 2022a;Yu & Smith, 2012). There is no "onesize-fits-all" characterization of human input, and any model of learning (language learning included) needs to account for and be robust to this massive variation.…”