“…When "quality" is defined, descriptions are for speech, not signs. Here is a sampling of the characteristics of caregiver speech that have been defined as "quality": higher quantity of language input (e.g., more words; Dwyer et al, 2019;Hart & Risley, 1995;Hoff, 2003;Hoff & Naigles, 2002;Gilkerson et al, 2017;Huttenlocher et al, 1991;Levine et al, 2020;Rowe, 2008Rowe, , 2012Vanormelingen & Gillis, 2016); use of "rare" words, lexical diversity, and lexical complexity (e.g., Hart & Risley, 1995;Hoff, 2003;Hoff-Ginsburg, 1991;Rowe, 2008Rowe, , 2012Scott et al, 2020); syntactic/sentence/structural complexity and longer utterances (e.g., Hirsh-Pasek et al, 2015;Hoff, 2003;Rowe, 2008); decontextualized language (e.g., Bernstein, 1971;Rowe, 2012); affirmations (as opposed to prohibitions; e.g., Conger et al, 2010;Hart & Risley, 1995) and the limited use of "direct commands" or "directives" (e.g., Fannin et al, 2018, Hart & Risley, 1995Hoff-Ginsburg, 1991;Rowe, 2008;Tulviste & Tamm, 2023) referential or didactic language and iconic and deictic gestures (e.g., Hirsh-Pasek et al, 2015;Kuchirko et al, 2020;Kuchirko et al, 2018;Romano & Windsor, 2020;Rowe & Goldin-Meadow, 2009;Tamis-LeMonda et al, 2018;Tamis-LeMonda et al, 2013); dyadic conversational turn-taking (e.g., Hirsh-Pasek et al, 2015;Leffel & Suskind, 2013;…”