Developing the implicit association test to uncover hidden preferences for sustainable drainage systems.

Understanding public perceptions of Sustainable Drainage Systems (SuDS) is critical for addressing barriers to their implementation. Perceptions are typically evaluated using explicit measures (e.g. questionnaires) that are subject to biases and may not fully capture attitudes towards SuDS. A novel image-based application of the Implicit Association Test is developed to investigate unconscious perceptions of SuDS in public greenspace and combined with explicit tests to evaluate perceptions of greenspace with and without SuDS, focusing on a sample population in Newcastle-upon-Tyne. Greenspace with or without SuDS is perceived positively by the sample population. Overall, respondents implicitly and explicitly prefer greenspace without SuDS and perceive greenspace without SuDS as more attractive, tidier and safer. The wide distribution of scores for SuDS, nonetheless, suggests a range of opinions and illustrates the complex nature of preferences for the use of greenspace. That the strongly negative explicit scores were not reflected in the implicit tests may suggest that explicit attitudes towards tidiness and safety may not be deep-rooted and are subject to social bias. Combined explicit and implicit tests may help us to understand any disconnect between expressed positive attitudes to natural spaces and behaviours around them and inform SuDS design to increase public acceptance. This article is part of the theme issue 'Urban flood resilience'.