Introduction: Making Sense of Performance Information There has been a huge growth in published performance information about public organisations and services in recent years aimed at citizens and users, including scorecards, league tables, and other published metrics. This information potentially affects citizens’ perceptions of services and their interaction with services and their associated institutions, especially political voice, including voting and lobbying, and choice of service (Dowding and John 2012; Hood 2006; James 2011a; Olsen 2015c). Recently a strand of experimental research has developed on this topic analysing citizens and users’ contact with performance information, how they make sense of it, the effects on them, and their responses (Bækgaard and Serritzlew 2016; James 2011a, 2011b; James and Van Ryzin 2017a, 2017b; Olsen 2015a, 2015c). This chapter identifies the contribution made by experimental methods, including in combination with psychologically informed public administration theory, towards understanding these processes and outcomes and the potential of this approach. The experimental method is especially valuable in this context because non-experimental, observational, methods struggle to identify the causal effects of performance information on citizens. Performance information varies in its availability, format of presentation, and incorporation of benchmarks for comparison in ways that are often correlated with a range of factors. Notably, differences in performance information are often related to variation in service sector, type of audience, saliency of the measure, policy makers’ incentives for presenting data in a certain manner, or citizens’ use of information. These factors are often themselves correlated with the effects of performance information per se, making it difficult for researchers using observational methods to disentangle the effects of the information from the influence of these other factors. For example, citizens who are already favourably disposed towards a public service may be more likely to seek out information about it. An observational study unable to control for this latent characteristic risks conflating citizens’ initial disposition with the effect of being exposed to performance information about the service. Experimental research offers a promising way of understanding how citizens are influenced by performance information. This information is a factor that is relatively easy to manipulate experimentally, in contrast to both macro-institutional features of the public sector, for example the form of governmental system, and citizens’ own personal characteristics, for example socioeconomic status or gender.