The Effect of Semantic Support on Word Learning

The goal of this clinical trial is to compare word learning outcomes in late talking toddlers who are taught different types of words. The main question it aims to answer is if teaching words that come from categories that children already know (e.g., animals) will aid overall word learning. Children will take part in the Vocabulary Acquisition and Usage for Late Talkers (VAULT) word learning treatment and be taught words from more familiar or less familiar categories to see which group learns more words overall.

Children will be assigned to either the familiar or less-familiar word group. All children will receive 8 weeks of Vocabulary Acquisition and Usage for Late Talkers (VAULT) word learning treatment (2x/wk for 30 minutes each session). The investigators will measure how well children learn the words they are taught as well as the words that are in the environment, but not explicitly taught (control words). This will help us know if their learning is due to treatment or maturation. The investigators will compare children to themselves (taught words v. control words) to ensure that the overall treatment is working. Then, the investigators will compare children in the familiar word group to children in the less-familiar word group to see which group learns more overall.

Using treatment effect sizes, children will be compared to themselves (treatment words v. control words) and across groups (familiar word group v. less-familiar word group).

In this condition, children will learn new words that come from semantic categories (e.g., animals, body parts) from which they currently understand at least several words.

In this condition, children will learn new words that come from semantic categories (e.g., animals, body parts) from which they currently understand few or no words.

The investigators will count the number of spontaneous and probed productions of target and control words and calculate a treatment effect size (d).

The investigators will measure the number of words learned and rate of words learned as reported by the parent on the MCDI starting prior to treatment, and measured during, immediately following, and 4-6 weeks after treatment.

The investigators will use probe data and parental report to determine how many words the child retained from treatment.

Inclusion Criteria: Native English Speaking Pass pure tone hearing screening or medical report of normal hearing 2-3 Years of age MCDI expressive scale <10th percentile Exclusion Criteria: Parental report of other diagnoses Enrolled in concurrent treatment elsewhere Nonverbal IQ <75 as measured by the Bayley scales Parents unable to consistently bring child to treatment sessions