Assessment pulls teachers in many directions: it can help them to adapt their teaching to meet the needs of the children, but it can also help to skew the curriculum in the direction of things that are easily tested. There is a wealth of evidence showing the impact of Assessment for Learning (AfL) but is it really possible for whole-school assessment systems to support learning? The Teacher Assessment in Primary Science (TAPS) project, which is funded by the Primary Science Teaching Trust (PSTT), aims to support teachers to make the most of assessment, improving validity, reliability and manageability. The first year was spent examining the huge variety of strategies and processes currently used in English schools. The team worked with local project schools and analysed submissions for the Primary Science Quality Mark (PSQM) (see Davies et al., 2014). In addition, the author visited a selection of PSTT College Fellows whose stories are summarised in this article.