All living systems share many properties, including hardly predictable behaviours, due to the differences between individuals and the chaos in natural environments. The reductionist approach to the interpretation of these phenomena suffers from the oversimplification of the factors involved in the quest for universal ''scientific” explanations. The validation of scientific paradigms is based on the consensus of leading groups who decide what is true and what is not. This means that all events - not only conflicting opinions but also conflicting raw data - not fitting with the official scientific truth were never published, which indirectly supported the correctness of the experts’ choice. With the advent of Web 2.0 and the freedom of publishing, the number of these not fitting events has dramatically increased. Yesterday, data were supplied to the reader with the interpretation. Now the reader has to wade through a huge amount of data and opinions in each field. Extracting the information you need from the garbage requires a strategy. Strategy is a science by itself. In the specific case of knowledge the first step is to define knowledge. The aim of life sciences, medicine and social sciences is to modify the reality when it is no longer sustainable, whatever it means in every single situation. I have to know how my system works to modify it. Knowledge is the information that allows me to succeed in my tasks. Tasks must have an assessable target. All information which is useful and therefore processed to attain the target will be 'targeted knowledge'. Information can be selected on the basis of its congruence with the internal rules of the system. In Web 2.0 we found proper tools to test this approach. We implemented a web application - which aims for easier identification of the molecular basis of diseases - structured in Rules, Reports, Items, Pathways and Tools referring and linking each other. The use of tags allows and fosters a free and personal use of information to create original knowledge. Users can follow and open innovative paths each time answering a different question, re-combining the fitting information. Our application is an example of advanced Problem Solving: the patient as a whole, not as a single symptom, has to be understood as a part of the living world (Gaia, with its rules) whose components (Items, Pathways) are described in their multiple roles and connections. The Web allows easy access to information, the program allows the network creation, the Rules drive the selection of the information and become more and more stable the more they evolutionary adapt to the reality; something like DNA, carrying millions of years old sequences in an ever changing world.