MacArthur-Bates Communicative Development Inventory for SLPs

 The MacArthur-Bates Communicative Development Inventories (MB-CDIs) are parent-reported questionnaires in the form of checklists. These questionnaires capture pertinent information regarding a child’s developing abilities. Such abilities include vocabulary comprehension, production, gestures, and grammar. The inventory consists of three forms: a long form, a short form, and an advanced form for ages 30-37 months.

Key Components

• The inventories are norm-referenced, based on the performance of 1,789 normal-developing infants and toddlers 8 to 30 months old. 
• The forms, or inventory checklists, were modified to assess spoken and signed vocabulary separately. 
• The CDI takes about 20-30 minutes to administer.
• There are three versions: infants 6 to 18 months, toddlers 18 to 30 months, and children 30 to 37 months.
  • The infant form assesses receptive and expressive vocabulary and acknowledges the use of communicative and symbolic gestures.
  • The toddler form assesses productive vocabulary and the early phases of grammar.
  • The most advanced form assesses vocabulary production and grammar.

Language Versions and Adaptations

• The Spanish and English versions of the CDI are valid and reliable.
  • Research shows that these versions are effective with children who have cochlear implants, children on the autism spectrum (ASD), and children with a cleft palate.
• The inventories have been adapted to other languages, including Chinese and American Sign Language, and dialects, such as Cuban Spanish. Some adaptations require continued research to be deemed valid and reliable.

The Importance of English, Spanish, and Bilingual Lexical Development 

The MacArthur-Bates Communicative Development Inventories address the importance of capturing the bilingual lexicon of an individual. The lexicon, or productive vocabulary, is the “mental dictionary.” This is the earliest reflection of a child’s language knowledge because it precedes multi-word combinations and syntax (Pearson, 1998). It is also fundamental to language learning and use because it serves as a building block for other linguistic domains (Bassano, Maillochon, & Eme, 1998; Kirk & Pisoni, 2000).

Lexical Development Research

Research has demonstrated that Spanish monolingual development resembles English monolingual development in rates and patterns of lexical production (Hernandez-Pina, 1979; Peraita, 1986). Research has also shown that bilingual acquisition utilizes analogous linguistic systems as monolingual development. It proceeds comparably in both sequence (De Houwer, 1995) and rate as monolingual children (Patterson, 2004; Pearson, Fernandez, & Oller, 1993). Additionally, researchers such as Pearson et al. (1993) emphasize that failure to measure both languages in the bilingual’s lexicon significantly undervalue their productive vocabulary skills.

Linguistic Benchmarks 

Using tools such as the English and Spanish MB-CDIs allows clinicians to better establish linguistic milestones for their bilingual population. This allows for an accurate evaluation of the student’s lexical development so that intervention can be provided when benchmarks are not met (De Houwer, 1995; Pearson, 1998).

How the CDI Calculates a Bilingual Score: Total Conceptual Score

A bilingual score, or total conceptual score, is derived from a list of the conceptual matches between the English and Spanish forms, developed by Marchman (1999). This score is necessary since bilingual children’s productive vocabulary is distributed across two languages. The bilingual score is calculated based on the verbal labels for concepts on the CDI and IDHC (Inventario del Desarollo de Habilidades Comunicativas), and it represents the number of concepts expressed, regardless of the language.

Bilingual Score Guidelines

1. A concept has more than one verbal label in English (e.g., chicken, hen), but only one label in Spanish (e.g., gallina).
2. A concept is represented in only one of the languages (e.g., rooster).
3. A concept has multiple labels in both English (e.g., sofa, couch) and Spanish (e.g., sofá, sillón).

A Note to Clinicians

Clinicians working with bilingual children can use the MB-CDI to establish the English, Spanish, and Bilingual lexical skills of their students. Since lexical development is important to later language learning, tools such as the CDI Words and Sentences Form and the IDHC Palabras y Enunciados Form can be utilized to determine a child’s present level of communication, while also taking into consideration their bilingual language skills. Clinicians are encouraged to visit the MacArthur-Bates Communicative Development Inventories website for further details and information, including the list of matched concepts for calculating the bilingual score.

Checklist for SLPs to Reference

• Carefully read all written instructions at the beginning of each section.
• Remember that it is based on parental observation and reporting.
• Select the appropriate version of the MacArthur-Bates CDI per the family’s and SLP’s assessment of the child’s language ability.
• Visit the MacArthur-Bates CDI website to see updated information regarding new instructions.

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