of fuel use, F, and the Fobserved Fsimulated difference was found to be insignificant.4.3.2. Step twoThe derived model was used in the final national level generalisation of the fossil energy use in the primary Danish agricultural sector. A linear scaling procedure was used, where the estimated average energy use for each crop and animal type was multiplied by the areas of crops and the namber of animals according to national agricultural statistics (criteria 3). The simulated and lineally upscaled energy use embedded in each of the accounted energy carriers was similar to the expected energy use according to national statistics, with a total difference of less than 3% (Dalgaard et al., 2002). In this case, it was concluded that the applied linear scaling procedure was sufficient for the step two generalisation (criteria 4).5. InterdisciplinarityInterdisciplinary means working across traditional disciplinary boundaries. For science in general, this can lead to creative breakthroughs, the identification of oversights, and provide more holistic solutions than work within single disciplines (Nissani, 1997). For agroecology, the specific issue is its continued growth from its roots in agriculture and ecology to include relevant aspects in sociology and economics. This development is desirable both because humans are an integral and important part of food producing systems and because it is necessary if decision-makers are to act on the basis of both ecological, social and economic principles (Wood, 1998).Achieving interdisciplinarity will require the removal of the barriers to the flow of information between the disciplines relevant to agroecology. These barriers include mind set and communication, where science has developed into increasingly specialised disciplines, talking different languages and having different areas of interest. Ideally, one could call upon scientists with a more generalist background to assist in communication between specialists but institutional barriers within modern science mean there is no encouragement for such creatures to flourish. These barriers are both physical and organisational. The physical barrier is that scientists from the different disciplines that interact with agroecology are normally in different institutes or departments, often in different physical locations. With the developments in information technologies and infrastructures this barrier may be less than it once was but the lack of social interaction will continue to be an obstacle to collaboration. The organizational barrier relates to the way in which science reward researchers via the provision of resources and career advancement. This depends heavily on the publication of papers in peer-reviewed scientific journals. Here the researchers within agroecology are faced with new opportunities but also several problems. The challenge of scaling is encouraging the development of novel experimental methodologies, e.g. through the combined use of modelling, observational science and advanced statistical mapping procedures (Riley, 2001). However, for the more reductionist scientists, integration to higher hierarchical levels, e.g. from the field to the farm level, means fewer opportunities for controlled experiments, experiments of greater duration and more time spent communicating with scientists from other disciplines. The experiments are likely to provide results that are more difficult to generalise than is common for more reductionist disciplines. However, as discussed earlier, the norms and social position of