Prof Tim Cole is applying for funding to further develop the SITAR method of growth curve analysis. There are three distinct objectives: to extend the SITAR methodology, to work with collaborators to apply the method to their own existing data, and to develop a library in the R statistical language35 to make the method more accessible to other researchers. The use of ALSPAC data relates to objective 2, and complements work already planned as part of Laura Howe's MRC Fellowship.