Cluster randomised control trial of an early childhood literacy intervention to improve literacy and language outcomes in preschool aged children

The following will be assessed annually from 12 months of age:
Measures of emergent literacy:
1. Who am I? An Australian measure for assessing the cognitive processes that underlie the learning of early literacy and numeracy skills in 4-7 year olds. It provides three numerical sub-scores (copying, symbols and drawing) and a total score out of a possible 44. Normative data are available for more than 4,000 Australian children, and its inclusion at 4 years in the "Growing Up in Australia: Longitudinal Study of Australian Children" (LSAC; an Australian government initiative that addresses a range of questions about children's development and wellbeing) will provide comparative data for a further 10,000 children.
2. Children's Test of Non-Word Repetition (CTNWR) is a measure of phonological memory, which provides information about word decoding ability and word attack skills; it is highly reliable even in preschool children and published norms are available.
3. Concepts About Print (CAP) This is a checklist of knowledge a child has about books and the function and conventions of text and books.
4. Preschool and Primary Inventory of Phonological Awareness (PIPA) This measure has six subtests that assess a child’s ability to detect, isolate, manipulate and convert sound units and is normed on Australian children.

Language measures:
5. Peabody Picture Vocabulary Test (PPVT): A widely-used measures of receptive vocabulary, with excellent norms; provides standard scores and is being used in both the "Early Language in Victoria Study" (a longitudinal study of language development in Victorian children funded by the National Health and Medical Research Council) and LSAC.
6. Clinical Evaluation of Language Fundamentals-Preschool (CELF-P): This widely-used language assessment tool provides Total, Receptive and Expressive Language standard scores.

The following will be assessed annually from 12 months of age:
1. Literacy activities and environment: STIM Q is an orally administered questionnaire that assesses cognitive aspects of the home environment. The READ subscale focuses on the number and variety of books in the home and frequency and quality of shared reading activities. It has a 0.55 correlation with the Home Observation for Measurement of the Environment (HOME) inventory, the gold standard of the environment.
2. Measure of language progress: Macarthur Communicative Development Inventories (MCDI; 12 months, 2 years, 3 years): The age-appropriate versions will be completed, i.e. at 12 months - MCDI (Words and Gestures) scale, which focuses on vocabulary comprehension and production; at 2 years - the MCDI (Words and Sentences) scale; and at 3 years – the MCDI III, which includes a 100 item vocabulary list, twelve sentence pairs for assessing grammatical complexity and twelve yes/no questions concerning semantics, pragmatics and comprehension. Widely used in Australian and internationally, these measures are acceptable, well validated for English-speaking children, provide continuous standard scores, have known predictive value, and are felt to be among the most reliable early measures of language development.
3. Measure of developmental progress: Parents’ Evaluation of Developmental Status (PEDS): comprises ten questions eliciting parent concern about a broad range of developmental and behavioural domains, including receptive and expressive language, written at a Year 5 level. Sensitivities of 74-80% and specificities of 70-80% have been reported against gold-standard testing for developmental disabilities. The questions will be supplemented with similarly-formatted questions probing concerns about early interest in listening to and looking at books.