This Special Issue is titled 'Quantitative Analysis of Behavior'. The 37th Annual Meeting of the Society for the Quantitative Analyses of Behavior (SQAB) took place at the McCormick Place Convention Center (Chicago, IL) May 22-May 24, 2014. Presentations from that conference are reported in this special issue as reviews, theoretical papers or reports of original research. Quantitative models of behavior can to some look like an impenetrable forest of equations, assumptions, and parameters. To others those trees provide the wood to build frameworks for assisting our understanding of forces that control behaviour. In this special issue, quantitative models of behaviour are examined from philosophical, theoretical, experimental and applied perspectives. The variety and breadth of approaches and areas of study covered by contributors highlight the continued importance and value of quantitative analyses to our understanding of behavior.