Five years ago, I wrote a post about COAST , a method of sequential testing proposed by Frick (1998). Time for a follow-up. In this guest post, my student Yiyun Liao, with the help of my colleague Steven Verheyen, writes about her experience using this method. She concludes with some tips about using COAST and about the importance of performing simulations and preregistering your research. Yiyun Liao Department of Psychology, Education and Child Studies Erasmus University Rotterdam, Netherlands liao@essb.eur.nl Recently I, together with Drs. Katinka Dijkstra and Rolf Zwaan, conducted a study on two English prepositions: to and towards . Instead of following a conventional fixed-sample testing method, we adopted a flexible sequential testing method based on Frick’s COAST method (Frick, 1998). A very interesting case occurred after we finished our data analysis. The Study The study was intended to replicate what we had found in a previous study on two Dutch preposit