Student performance data from a post-92 university in the United Kingdom showed that, for a substantial minority of programmes, there was a general dip in marks between Years 1 and 2. Longitudinal and cross-sectional data were analysed in order to ascertain whether the latter (with its advantage of a more rapid production of results) would make an adequate proxy for the former: the analyses suggest that it can do. The article discusses a number of factors that have to be borne in mind, particularly if cross-sectional analyses are undertaken.