As parents, we are often interested in following the development of our children and finding out how much they have learnt at different points in the early years of life. Understanding what children know and how they learn is also important for researchers interested in understanding their development. With this in mind, together with researchers from the University of Oslo, researchers from the University of Göttingen have developed the Babylex app, which will allow parents and researchers alike to follow the early vocabulary development of their young children.
Babylex is a freely available app (for use on Android and iOS devices) that will help parents and researchers estimate the number of words a child knows. Babylex will also provide parents and researchers with a percentile score of a child, which offers a comparison between the number of words a child knows relative to the number of words known to other children who are the same age and gender.
This information is computed on the basis of a two-minute test that parents can take on their mobile devices, where they indicate which of 25 randomly selected words their child already understands or produces. Babylex is currently available for use with German children (from 18- to 30 months), American children (from 16 to 30 months) and Norwegian children (from 16 to 36 months). Efforts are ongoing to extend to other languages.
Parents can take the test as often as they like, to follow their child’s development within the age ranges the tests have been developed for. They can also store this data on their phones to recall results of previous tests.
The algorithm behind Babylex draws from a free database (wordbank.stanford.edu), containing anonymised data from thousands of children related to the words known to children at different points across in their development.
The data on Wordbank is collected using standard vocabulary questionnaires where parents indicate which of between 400 to 600 words their child already knows. Such questionnaires are routinely used in clinical assessments of children. Babylex then estimates the number of words individual children know based on the overlap between the responses on the app and the responses in the database.
Tests with children in the Göttingen child language laboratory, Wortschatzinsel, find remarkable consistency between the vocabulary estimates provided by the app and the long-form vocabulary questionnaires, despite that the test on the app takes less time to complete.