Which forms of knowledge are most appropriate for informing and influencing policy-making? Are some types of knowledge more acceptable or suitable than others? These are questions that have been addressed by ODI’s Research and Policy in Development (RAPID) programme. Jones et al. (2009), for example, argued that traditional science and research are not well equipped to deal with the complexity of policymaking and development. The authors called, therefore, for multi-, interand trans-disciplinary research approaches for policy-influencing. In this Background Note we aim to go one step further. We start by suggesting a way to classify different types of knowledge that aim to influence policy. We then use the classification to analyse case studies from three South-East Asian countries: Indonesia, the Philippines and Vietnam. We conclude with suggestions on the usefulness of the development of classifications – a taxonomy – of knowledge types. The underlying proposition is that when we deal with complex processes, such as policy-making, a taxonomy of knowledge types can be a useful tool to help us organise, understand and access knowledge. On the one hand a taxonomy can help various knowledge producers (i.e. not only researchers) to present and communicate what they know and have learned. On the other, it can be useful for knowledge users such as policy-makers and bureaucrats to appreciate the value of a diversity of knowledge sources to inform their own decision-making (Pawson et al., 2003). This Background Note is, therefore, an experiment. It suggests a taxonomy that we begin to flesh out with the analysis from the three country case studies about the simplification of administrative procedures. Two countries, Indonesia and the Philippines, have experienced military rule: Indonesia under Mohamed Suharto from 1967 to 1998 and the Philippines under Ferdinand Marcos from 1972 to 1986. Vietnam did not experience such dictatorship but emerged from decades of war in 1975 and in 1986, under the leadership of the Communist Party, started the Doi Moi reform which included a gradual transition to a market oriented economy. All three countries have enjoyed rapid economic and population growth rates following the 1997 Asian economic crisis. This has left their governments struggling with the typical challenges of the transition of a country from lowto middle-income status: growing income inequality between urban and rural areas, unequal access to basic services for all citizens, how to attract foreign investment and promote small and medium enterprises, and how to prevent the emergence of ethnic tensions. To respond to these challenges all three countries have undertaken wide ranging public administration reforms to enhance the effectiveness and efficiency of service provision to reduce transaction costs in public administration procedures and respond to the demands of their citizens for greater participation in decision-making processes. First, let us turn to the characteristics of the taxonomy of knowledge types that will be informed by the case studies. Technically sound and politically achievable? A taxonomy of knowledge types and their influence on governance in three South-East Asian countries