- This slide defines the symbol system used in the presentation: an analog amplifier having two inputs and an output. If the inputs are equal, the output is neutral, if the inverting input (-) is greater than the non-inverting input (+), the output is negative, and if the non-inverting input is greater than the inverting input, the output is positive. Such a device can be used to compare two inputs and make a logical decision about their relative values. The energy delivered to the output summarizes the relative positions of the inputs.
- The term "negative feedback" seems a bit...well, negative! But really it is a positive concept, because this is the thing that keeps us from going off the deep end. When we invest undue energy in our personal biases and filters, someone needs to give us a douse of cold water once in a while to bring us back to equilibrium. In the analog world, an operational amplifier is a comparator with the output feeding back to the inverting amplifier. So as energy is applied to the non-inverting input, the output begins to rise, but since that increase is also fed back to the inverting input, the rise is attenuated or controlled. An operational amplifier behaves in such a way that the output always strives to make the inputs equal.
- We can use this symbol system to describe behaviorism. The behaviorist model applies corrective energy to the controlled object until the object behaves just like an external reference. Envision a pigeon as the controlled object, and a ping pong champion as the referennce object and you can see (shudder!) what Skinner had in mind.
- There are models of control that are not quite so reductionist. The Pask Model is interesting, because it allows for the mutual correction of two equal participants in the learning process. Pask's model calls forth two "cognitve systems" (you and me, teacher and learner, us and them, them and me, or me and (shudder!) AI. The players hash out their differences over a concept, correcting each other's misconceptions until there is total agreement between the two.
- So, you invest all this energy until you reach agreement! So what? Pask suggested that value can be derived from the resulting concept, so maybe it is worth saving. The Pask model includes a method of archiving public concepts (concepts that are shared by all parties involved). The archive is called an entailment mesh, a knowledge base of public concepts.
- Any group, community, or society is, by Pask's definition, a cognitive system. The community learns from its individual participants, and each individual learns from the community.
- USENETis a medium which allows for the creation of communities of learners. Ongoing conversations are a means of knowledge construction within such communities.
- There is value to be derived from these conversations, and it is worth the effort to archive it. One form of entailment mesh is the USENET FAQ (a knowledge base of frequently asked questions [and answers]).
- A newcomer can quickly locate the established dogma of a community by taking the time to browse the entailment mesh. One can learn the jargon, the basic concepts, the issues that are most frequently addressed by those who fully engage in the culture.
- In addition, one can learn a great deal by lurking. It is here that peripheral participants learn the biases, the values and the behavior patterns of the regulars in a practioner community. Lurking has a negative connotation, but it is a necessary step in becomming familiar with the culture of a community.
- The apprenticeship model is not unlike the model just presented. It allows the apprentice to observe and learn for a long period before he engages in full participation. Once having learned the basics: the jargon, the values, the rules of participation, he then may begin to participate as a peer, offering his own perspectives which can influence the community and construct new knowledge in the process.
Martin Ryder
Storage Technology Corporation