While seldom made explicit, concepts regarding ownership of knowledge vary - and often, this variation obfuscates the discussion. Making them explicit may help to reduce confusion and misunderstanding.
One view is that all the knowledge existing in the world is in the public domain, free for anybody to use, except that knowledge which is privatized, which is protected under patents, plant variety rights and other IPR laws. This, in fact, is the 'modern' view or concept - or at least the concept which implicitly underlies most IPR laws. It is actively advocated by large corporations, notably those operating in sectors where IPR play an important role (e.g. pharmaceuticals).
There is, of course, an exchange between the two domains: generally, it is recognized that, to some extend, new or protected knowledge draws on existing (public domain) knowledge. This is not perceived as a problem, since knowledge also moves from the private to the public domain; IPR protection, after all, is time-limited (20 years for patents, life plus 50 years for copyrights etc.) - thereafter the knowledge becomes part of the public domain and contributes to its expansion, for the benefit of all. Therefore it is argued that, ultimately, all benefit from the IPR system.
Source: G. Dutfield
Others consider that the above mentioned point of view oversimplifies the situation. They hold that within the private domain, one can distinguish knowledge protected according to customary law and practices, in addition to knowledge protected by IPR laws. In theory, there may be an overlap, signifying that knowledge protected by customary law can also be protected by IPR laws; but in practice (see chapter 4) the likelihood of this happening is small. Moreover -though not very relevant in this context- there is other knowledge in the private domain, for instance personal secrets, which are not explicitly protected.
Source: G. Dutfield
The shift in perception highlights that it is -at best- questionable to assume that traditional knowledge is free for anyone to use. Often, there are customary laws which apply to this knowledge, and which may restrict the rights of third parties to access and use it. In order to preserve and sustain this knowledge, the customary laws governing it should be respected. Moreover, holders of traditional knowledge should be compensated in case their knowledge is used by others, especially if it is considered important to motivate them to continue generating new knowledge. In fact, a policy that considers traditional knowledge important, but does not recognize and respect the rights of its holders, is doomed to fail.
A third conceptual framework holds that there are three domains of knowledge: individual, community and public. Different rights are associated with knowledge in the different domains, which however overlap. This framework explicitly distinguishes between individual and community knowledge, and considers that neither is part of the public domain. In this view, the fact that a community's knowledge is known to several hundred people, does not imply that it is part of the public domain; if in a company, several hundred people work together on a research project and share the same knowledge, it is still considered (the company's) private knowledge - and there is no a priori reason for different treatment in case the people sharing certain knowledge belong to the same community instead of company.
Secondly, this concept recognizes that there are variations in the amount of knowledge that different members of the community have. For example, within the community domain, there is knowledge which is known to everybody, and which is used by everybody, as well as knowledge which is not (or: no longer) used by anybody, but which is known to everybody, or to most people.
But there is also knowledge which is used by the community but produced by a few experts, e.g. healers or herbalists, as well as knowledge which is used and produced by individuals, but of which the community is aware (area a).
Source: A. Gupta
This model furthermore implies that the rights of individuals who produce new knowledge should differ from the rights of other community members. Nevertheless, the community does have certain rights, since by conserving biodiversity, the community has enabled creative individuals to produce knowledge based on those biological resources. Therefore, the community deserves a share of the benefits which may accrue to innovators.
Finally, knowledge which has been documented and published obviously is in the public domain. Individual or community knowledge can be brought in the public domain by publication (area b & c), and it is important to realize that, when outsiders document knowledge belonging to a community or an individual, by bringing this knowledge into the public domain, they take away the rights of that community or that individual17.
17 Once people lose the rights over their knowledge, their chances of obtaining the ensuing benefits are considerably reduced too.