science are changing as the presumption that science is sacrosanct withers and scientists increasingly have to argue their value to human endeavour. As agriculture is a mature science, compared to other disciplines such as biotechnology or microelectronics, agroecologists may find themselves in the forefront of this development.6. Procedures and strategies to address agroecological questions at different scalesIt is argued here that studies of how to cross the barriers of scaling and interdisciplinarity should be central issues for future agroecological research projects. For soil sciences, Bouma (1997) drew similar conclusions and appealed for new methods to deal with the issues and proposed a seven-step procedure for research in sustainable management of agricultural soils (Bouma et al., 1998). This procedure was found useful to address agroecological questions (Wagenet, 1998) but problems were encountered in integrating socio-economic information and in the issues of hierarchy and scale (Dumanski et al., 1998). The framework presented here (Table 2) builds upon Bouma et al.'s (1998) procedure and corresponds to the application of the scientific method of natural sciences-observing, meassuring and interpreting - stressed in the introduction to the agroecology book by Carroll et al. (1990). The difference is that the framework presented here was extended to distinguish between hierarchy and scale in the form of the defined linear, non-linear or hierarchical scaling procedures. In addition, the present framework included a test (criteria 4) in the defined scaling procedure and an iterative exploration of scaling functions that proceeds until the error does not exceed a sensible threshold value (Table 2). To develop such scaling functions, comprehensive decision-support systems have been developed (Bierkens et al., 2000) but to date only methods to answer hard agroecological questions have been included, while the integration of information from the soft agroecological ones is not included. The framework of hierarchy and scale presented here is similarly bound to hard agroecology but provides a hint at a starting point for interdisciplinary research projects. This would typically be a common problem of sustainability, investigated by both soft and hard researchers, corresponding to the criteria l problem in the framework. However because the soft sciences do not produce pure quantitative results, it might not merely be a question of currency shifts - for example from the physical units of an agronomic study to the monetary units of an economical study (Squire and Gibson, 1998)- followed by the traditional sca1ing procedure of criteria 2-4. Instead, criteria 2-4 could be interpreted as a communicative process (Bawden, 1995), where statements regarding solutions to the common problem are compared at spatio-temporal scales of relevance for decisions.One example where the resu1ts from soft and hard sciences differed, and interdisciplinary research would gain knowledge is illustrated in the recent debate concerning the possible benefits of introducing a "golden rice variety" (Schiermaier, 2001). In contrast to traditional varieties, the golden rice is genetically engineered to contain Vitamin A precursors, a deficiency of which causes blindness and other illnesses. One of the inventing plant scientists predicted the introduction of this new variety to solve the "unnecessary death and blindness of millions of poor every year"