What Are the SUGAR Norms?
SUGAR — *Sampling Utterances and Grammatical Analysis Revised* — is a streamlined language sample analysis protocol introduced by Pavelko and Owens (2017). The SUGAR project simplifies traditional LSA into a 50-utterance sample with four core metrics: MLU in morphemes, Total Number of Words (TNW), Clauses per Sentence (CPS), and Mean Length of Utterance — Longest 5 (MLUL).
Why SUGAR matters. Older normative tables for language samples either required expensive software (SALT) or were grounded in tiny longitudinal samples (Brown 1973, Miller & Chapman 1981). SUGAR was the first free, large-sample (n=1,576), peer-reviewed normative reference for clinical language sampling published in the past decade.
What the table reports. Each row of the SUGAR norms gives the mean and standard deviation of each metric for a 6-month age bin from 3;0 to 7;11. The lookup tool here surfaces the row matching the child's age and shows ±1 SD as a typical range so you can see at a glance whether the child's sample is on, near, or below the population mean.
How to Use This Tool
Enter the child's age in years and months. The tool returns the SUGAR row matching that age:
- Mean and ±1 SD for MLU (morphemes), TNW (50-utterance total), CPS (clauses per sentence), and MLUL (longest 5 utterances).
- The full SUGAR table is displayed below the highlighted row so you can see how norms shift across age.
- Out-of-range ages clamp to the closest available bin (3;0 - 3;5 or 7;6 - 7;11) with a banner explaining the clamp.
Workflow. Run a SUGAR-protocol 50-utterance sample, compute MLU/TNW/CPS/MLUL with the MLU calculator and lexical-diversity calculator, then bring those numbers here to compare against age-matched norms.
SUGAR Metric Glossary
MLU (Mean Length of Utterance — morphemes). Total Brown-rule morphemes divided by total utterances. Single best summary of grammatical maturity in early childhood; plateaus around age 7-8.
TNW (Total Number of Words). Sum of all word tokens across the 50-utterance sample. Coarse but reliable index of overall productivity. Rises roughly linearly across the SUGAR age range.
CPS (Clauses per Sentence). Total clauses (main + subordinate) divided by total sentences. Captures syntactic complexity beyond MLU; sensitive to school-age grammar growth.
MLUL (Mean Length of Utterance — Longest 5). Mean morpheme length of the longest five utterances in the sample. A ceiling-style measure that shows the upper bound of the child's grammatical productivity, used by SUGAR as a sensitive measure of advanced syntax.
