Generate percentile scores for your own CDI administrations, for the major sections of the English (American) and Spanish (Mexican) Words & Gestures and Words & Sentences forms. Upload a CSV with columns for child ID, age in months, sex (optional), and any summary scores — your file is processed entirely in your browser and never uploaded anywhere.
san = (s) => s.toLowerCase().replace(/[^a-z0-9]+/g,"_").replace(/^_+|_+$/g,"")split_options =newMap([ ["None",null], ["Sex","sex"], ["Birth order","birth_order"], ["Caregiver education","caregiver_education"], ["Ethnicity","ethnicity"]])level_orders = ({sex: ["Female","Male","Other"],birth_order: ["First","Second","Third","Fourth","Fifth","Sixth","Seventh","Eighth"],caregiver_education: ["None","Primary","Some Secondary","Secondary","Some College","College","Some Graduate","Graduate"],ethnicity: ["Asian","Black","Hispanic","White","Other"]})level_sort = (split) => {const order = split ? (level_orders[split] ?? []) : [];return (a, b) => {const ia = order.indexOf(a), ib = order.indexOf(b);if (ia !==-1|| ib !==-1) return (ia ===-1?99: ia) - (ib ===-1?99: ib);return a < b ?-1: a > b ?1:0; };}
This scoring utility generates percentile values for each of the major sections of the MacArthur-Bates Communicative Development Inventories in English (Marchman et al., 2023) and Mexican Spanish (Jackson-Maldonado et al., 2003). Percentiles were generated with generalized additive models in the beta distribution family using monotonic P-splines over age, fit with gamlss; English norms are weighted to reflect US demographic characteristics (2020 census: maternal education, race, and ethnicity).
Norming values for the American English Words & Gestures form are identical to those in the 3rd edition of the User’s Guide and Manual (Marchman et al., 2023). Values for the American English Words & Sentences form are identical to those in the User’s Guide except that they have been extrapolated to 36 months. Values for the Mexican Spanish forms are based on the norming sample of Jackson-Maldonado et al. (2003), regenerated with the same statistical procedure (without socio-demographic weighting) and extrapolated to 36 months for Words & Sentences.
For administrations outside the normative age ranges (Words & Gestures 8–18 months; Words & Sentences 16–36 months), you can choose to generate no percentile (NA) or to score at the nearest normed age (e.g., a 20-month Words & Gestures administration scored against the 18-month values). Caution is advised when interpreting percentiles outside the normative ranges.