Knowledge may originate or be derived from the following origins or methods: -Observation or experience. This may be more or less sophisticated, ranging from a simple, "I saw" to carefully designed controlled experimentation. -Reason or logic. Taking other knowledge as data, by logical operations knowledge can be inferred. For example the theoretical construct, the electron, is derived by logical inferences from observations and experiment. Such knowledge, being derivative, can not be better than the knowledge upon which it is founded. -Modelling a situation sometimes allows those with a hands-on viewpoint to learn how-to do something. This pragmatic approach is often seen in computer programming. -Testimony. Knowledge based on the acceptance of testimony involves accepting what others say. For example, I only know that Kent is a county of England, that the First World War was horrendous. This seems to be a common way we get knowledge but is seen by philosophers as problematic. -Authority. Knowledge based on authority may rely upon the reputation of an individual such as Aristotle or Einstein or perhaps on institutional authority such as that of the Roman Catholic Church or Oxford University. So far processes have been mentioned by which knowledge is obtained. But, in obtaining knowledge there are typically two main kinds of knowledge that one can obtain. These two types of knowledge are typically labelled fallible knowledge and infallible knowledge. This book gives an excellent overview of these methods and how they are implemented and is designed to be a general overview of the topic and provide you with the structured knowledge to familiarize yourself with the topic at the most affordable price possible. The level of discussion is that of Wikipedia. The accuracy and knowledge is of an international viewpoint as the edited articles represent the inputs of many knowledgeable individuals and some of the most currently available general knowledge on the topic based on the date of publication.