The main objective of this paper is to describe the trajectory of Danish children's early lexical development relative to other languages, by comparing a Danish study based on the Danish adaptation of The MacArthur-Bates Communicative Development Inventories (CDI) to 17 comparable CDI-studies. The second objective is to address the feasibility of cross-linguistic CDI-comparisons. The main finding is that the developmental trend of Danish children's early lexical development is similar to trends observed in other languages, yet the vocabulary comprehension score in the Danish children is the lowest across studies from age 1 ; 0 onwards. We hypothesize that the delay is related to the nature of Danish sound structure, which presents Danish children with a harder task of segmentation. We conclude that CDI-studies are an important resource for cross-language studies, but reporting of studies needs to be standardized and the availability of published data improved in order to make comparisons more straightforward.

This paper presents a large-scale cross-sectional study of Danish children's early language acquisition based on the Danish adaptation of the MacArthur-Bates Communicative Development Inventories (CDI). Measures of validity and reliability imply that the Danish adaptation of the American CDI has been adjusted linguistically and culturally in appropriate ways which makes it suitable for tapping into Danish children's language acquisition. The study includes 6,112 randomly selected children in the age of 0 ; 8 to 3 ; 0, and results related to the development of early gestures, comprehension and production of words as well as grammatical skills, are presented.

The emergence of portable global positioning system (GPS) receivers over the last 10 years has provided researchers with a means to objectively assess spatial position in free-living conditions. However, the use of GPS in free-living conditions is not without challenges and the aim of this study was to test the dynamic accuracy of a portable GPS device under real-world environmental conditions, for four modes of transport, and using three data collection intervals. We selected four routes on different bearings, passing through a variation of environmental conditions in the City of Copenhagen, Denmark, to test the dynamic accuracy of the Qstarz BT-Q1000XT GPS device. Each route consisted of a walk, bicycle, and vehicle lane in each direction. The actual width of each walking, cycling, and vehicle lane was digitized as accurately as possible using ultra-high-resolution aerial photographs as background. For each trip, we calculated the percentage that actually fell within the lane polygon, and within the 2.5, 5, and 10 m buffers respectively, as well as the mean and median error in meters. Our results showed that 49.6% of all ≈68,000 GPS points fell within 2.5 m of the expected location, 78.7% fell within 10 m and the median error was 2.9 m. The median error during walking trips was 3.9, 2.0 m for bicycle trips, 1.5 m for bus, and 0.5 m for car. The different area types showed considerable variation in the median error: 0.7 m in open areas, 2.6 m in half-open areas, and 5.2 m in urban canyons. The dynamic spatial accuracy of the tested device is not perfect, but we feel that it is within acceptable limits for larger population studies. Longer recording periods, for a larger population are likely to reduce the potentially negative effects of measurement inaccuracy. Furthermore, special care should be taken when the environment in which the study takes place could compromise the GPS signal.

Using the Danish adaptation of the MacArthur-Bates Communicative Development Inventories (CDI), first language acquisition of 183 Danish children has been studied longitudinally on a monthly basis (8-30 months). Focussing on production, we study early lexical development from the very first word until roughly 100 words are produced, dividing this period into the stages of first-1, -10, -25, -50 and -100 words. We analyse Danish children's first words with respect to semantic-pragmatic content, sound structure, and composition of the early lexicon based on formal linguistic categories. Comparing Danish results crosslinguistically reveals both the overall typicality of Danish children's first words as well as striking differences for some single words.

Research has shown that contoids (phonetically defined consonants) may provide more robust and reliable cues to syllable and word boundaries than vocoids (phonetically defined vowels). Recent studies of Danish, a language characterized by frequent long sequences of vocoids in speech, have suggested that the reduced occurrence of contoids may make speech in it intrinsically harder to segment than in closely related languages such as Norwegian. We addressed this hypothesis empirically in an artificial language learning experiment with native speakers of Danish, Norwegian, and English. We tested whether artificial speech consisting of concatenated contoid–vocoid syllables is easier to segment than speech consisting of vocoid–vocoid syllables where the first segment is a semivowel and the second a full vowel. Contrary to what was expected, we found no effect of the phonetic makeup of the syllables on speech segmentability. Possible interpretations and implications of this result are discussed. Open Practices This article has been awarded Open Materials and Open Data badges. All materials and data are publicly accessible via the Open Science Framework at https://osf.io/rmjtg. Learn more about the Open Practices badges from the Center for Open Science: https://osf.io/tvyxz/wiki.