Indeed, disciplines can be interpreted as just administra­tive academic artifacts, which have lost their significance as an organizing principle of science during the last quarter century (Lele and Norgaard, 2005). For example, the bio­logical sciences have dropped the historic disciplinary dis­tinctions, e.g., between the plant and animal worlds and are organizing more according to the level of analysis from genes to organisms to ecosystems. The diversity of approaches within a discipline and the possible relatedness with an ap­proach of another discipline suggest forgetting disciplines and thinking in terms of scientific community (Lele and Norgaard, 2005). A scientific community is a group of scholars who share a characteristic. The characteristic can be (1) a subject, (2) assumptions about the underlying char­acteristics of the factors they study, (3) assumptions about the larger world they do not study and about how what they do study relates to the larger world, (4) the models they use, (5) the methods they use and (6) the audience they strive to inform through their research. Crucial, according to them, is recognizing that organizational charts of universities do not coincide with the most important markers of difference and similarity found on different dimensions and scales. This recognition facilitates crossing boundaries between scien­tific communities.

4.4.3 Barriers faced by integration
Interdisciplinarity is increasingly considered the ideal of research but it relies heavily on high-quality disciplinary re­search (Lockeretz and Anderson, 1993; Bruun et al., 2005; Kahiluoto et al., 2006). In applied sciences, such as agricul­tural and food sciences, integrative approaches are becoming more widely accepted in education, research and extension and in some contexts are increasingly demanded by funding organizations. Participation is also an approach increasingly demanded by donors of international research funding.
     Although disciplinary borders have always been crossed in research, integrative approaches are difficult to handle, not yet well understood and their adoption and wide ap­plication still face major constraints (Duncker, 2001). Seven major barriers for interdisciplinarity exist: structural, knowl­edge, cultural, epistemological (i.e., relating to the theory of knowledge), methodological, psychological and reception barriers (Bruun et al., 2005).
     The structure of organizational decision-making and the organizational norms affect the character of research and education. The current disciplinary organization of science has been criticized as hampering interdisciplinary research and educational programs (Bruun et al., 2005), though ob­viously there are numerous such ongoing programs and projects. Fragmentation starts with the structure of govern­ments, is present in the disciplinary organization of universi­ties and research institutes and is present in the contents of education and training programs.
     An important obstacle for interdisciplinarity is that scholars  who  review  interdisciplinary  project  proposals have no training in the quality criteria for interdisciplinary research and that boards of reviewers often don't cover the breadth of knowledge required to give full justice to inter­disciplinary research proposals. On the basis of an empirical study interviewing experimental researchers at major inter­disciplinary research institutes, main quality criteria include:

(1) Consistency with multiple separate disciplinary anteced­ents' (i.e., the way in which the work stands vis-à-vis what re­searchers know and find tenable in the disciplines involved); (2) Balance in weaving together perspectives (i.e., the way in which the work stands together as a generative and coherent whole); and (3) Effectiveness in advancing understanding (i.e., the way in which the integration advances the goals that researchers set for their pursuits and the methods they use) (Mansilla and Gardner, 2003). Scientists throughout much of NAE are primarily based on their refereed publi­cation output and its impact (measured in terms of impact factors and citations). Scientific journals with high impact factors tend to have little interest in applied interdisciplinary research and often have a disciplinary orientation.
     Cultural barriers include language problems (such as different technical terminology) and differences in method­ologies. Problems with communication and understanding across disciplines are seen by many as the main barrier for successful multi- and interdisciplinary settings (Bärmark and Wallen, 1980; Porter and Rossini, 1984; Bauer, 1990; Duncker, 2001; Pawson and Dovers, 2003; Helenius et al., 2006; Kahiluoto et al., 2006; Mäkelä, 2006).
     Epistemological problems occur when disciplines fun­damentally interact. Reception barriers appear when issues and assumptions that are dealt with are unfamiliar to the es­tablished disciplines and thus not easily accepted. Problems in paradigms, communication, organization and cognitive development are often faced in interdisciplinary research (e.g., Bärmark and Wallen, 1980). The creation of "trad­ing zones" for exchange and "interlanguages" (more or less elaborate) may be required for successful cooperation across disciplinary borders (Duncker, 2001). Many efforts failed partly because the representatives of the separate intellectual communities did not recognize the barriers created by their separate ways to understand and approach the problems (Bärmark and Wallen, 1980; Lele and Norgaard, 2005).
     Institutions that have a history of interdisciplinary orien­tation typically can move more quickly to adopt new initia­tives along these lines than those that do not (Feller, 2005). And a number of studies have indicated that the barriers for interdisciplinarity and participation can be overcome. Conceptual tools to overcome the most prominent barrier in interdisciplinary studies—communicating and understand­ing across the disciplinary borders—have been developed (e.g., Duncker, 2001; Heemskerk et al., 2003). It is an im­portant challenge for science education to improve profi­ciency in interdisciplinarity through a better understanding of the philosophy and theory of alternative approaches and methodologies in science. This can be achieved through development and adoption of appropriate procedures and tools for communicating and through practicing interdisci­plinarity (Venkula, 2006).
     Barriers faced by participatory approaches are largely similar to the barriers faced by interdisciplinary approaches but are often even higher for the former and more diverse as participatory approaches usually cover integration both horizontally among disciplines and vertically among dif­ferent actors. For participatory approaches involving non-academics from different parts of food systems and fields of life, communication is more challenging than in integrated approaches involving solely academics. Tools to facilitate