The Odense Longitudinal CDI-Survey The Odense Longitudinal CDI-survey is one of the core components of the project. The corpus is intended to 1) substan-tially increase the available acquisition corpora for the Danish language, 2) to facilitate the testing of hypotheses relating to inter-individual as well as intra-individual differences, which is possible due to the large number of informants, and 3) to facilitate cross-linguistic as well as cross-variety comparisons. The survey has been designed to first and foremost investigate the development of the early vocabulary, both in terms of comprehension and production. The survey is based on the parental reports, CDIs, on children's developing communicative skills. CDIs are comprehensive check-lists, and their overriding advantage in the study of children's language is that parents' vast and intimate knowledge of their children render the elicited information highly representative of both children's language comprehension and production as well as their overall linguistic knowledge. The period investigated, age 8-30 months, is divided up into two separate periods with corresponding versions of the CDI: Apart from vocabulary, the first version ("infant", age 8-16 months) includes gesticulation and social routines, whereas the second ("toddler", 16-30 months) includes early morphology and the first combination of words. For more information on the CDI, see below and under Links. In addition to investigating the age variable, the survey is designed to investigate gender difference in language acquisition. This is possible due to the equal distribution of female and male subjects. The final variable under investigation is the impact of regional varieties on development. This has been made possible by selecting the subjects from three main regions of different varieties, one of these being the standard Danish variety. The inclusion of the three standards will provide us with some interesting supplementary data in our general investigation of the interaction between phonetics and morphology and its role for language acquisition, that is, the effect of morpho-phonetics on early lexical and in particular early grammatical development The large number of subjects will serve as a solid basis for cross-sectional analyses (as well as for cross-linguistic and cross-variety comparisons), which will provide us with a general picture of Danish children's early lexical and grammatical acquisition. In addition, the longitudinal aspect of this survey will allow us to look into individual strategies of acquisition. For research within the project that makes use of the corpus, see The Interaction Between Inflectional Morphology and Phonology (-Orthography), Speaking and Writing and Early Lexical and Morphological Development in Danish Children.   Facts about the CDI-Survey * The Odense Longitudinal CDI-Survey is a large-scale study of the acquisition of Danish as a first    language in Danish children from the age of 8 months to the age of 30 months. * The survey runs from March 2000 to February 2002. * The survey has a total of 200 subjects, of which 50% are female and 50% male. * The subjects were all born in the first week of July 1999, thus they were all 8 months old at the onset    of the survey. * Subjects have been selected from the three main regions of different varieties of Danish - Jylland, Fyn    and Sjælland. * The survey is based on parental reports &endash; the MacArthur Communicative Developmental    Inventory (CDI). * Every month for 23 months the parents of the subjects receive and fill out a CDI-report, which they    then return to us for analysis. * An electronic database has been developed which includes detailed morphological and phonological    information about each lexical item according to the OLAM conventions. This enables sophisticated    linguistic analyses of the data. * Gender related information, based on questionnaires filled out by the parents, is also included in the    database.   The MacArthur Communicative Developmental Inventory - CDI The CDI has been developed by Developmental Psychology Lab, San Diego State University, San Diego, California, USA. The Odense Language Acquisition Project has adapted the original CDI for Danish. CDIs are parental reports on their children's communicative skills. Parents have a vast and intimate knowledge of their children's communicative skills, i.e., both their comprehension and production of language. They observe their children in a wide range of situations, making their knowledge representative of what their children know and are capable of. The CDI is designed for the purpose of accessing this vast, intimate, and representative knowledge and of putting this knowledge to use in a systematic and comprehensive way. With this it is possible to develop accurate profiles of children's communicative development and to do so cost-efficiently. There are two parts of the CDI: the Infant version (8-16 months), "CDI/Words and Gestures" and the Toddler version (16-30 months), "CDI/Words and Sentences". Each version is a comprehensive checklist of, first and foremost, the child's vocabulary production, thus ensuring the systematic reporting on the same items rather than random recollections of potentially very different items. In addition to this, the Infant version requests information concerning the child's vocabulary comprehension and use of gestures. The Toddler version requests information concerning aspects of the child's grammatical development. Vocabulary comprehension has been dropped from focus in this version, since at this stage in children's communicative development comprehension is too inclusive to keep track of. Futhermore, the check-list format enables easy adaptation into other languages, thus rendering the CDI an excellent tool for cross-linguistic developmental studies of infant and toddler language.