Many descriptive tools, when used alone, represent information and information systems inadequately or inefficiently. A photograph is a great tool for showing the visual detail of an arctic landscape to a Floridian who has never experienced cold air and snow, but not so good for showing him what the landscape feels like. It's better to both show a person a photograph of an arctic landscape and tell him: "The air there is cold, like air in a freezer. Snow feels something like orange sherbet, but it's fluffy and light. If snow melts in your hands, they won't get sticky."

Diagrams, language, and mathematical notation can often be used in different complementary combinations to make communication more efficient. Many times one of the tools is primary and another is secondary. In a biology textbook that uses diagrams to illustrate the concept of cell division explained by written language, the written language is the primary mode of communication because the diagrams are used to accompany, simplify, or clarify the detailed explanations.

Often, a collection of tools are used together to resolve a practical problem or to communicate its solution. For instance, Claude Shannon developed information theory because he was looking for a way to make telephone communication more efficient. A person can use information theory's various descriptive tools, such as diagrams of communication systems, written explanations of the theory, and mathematical formulae to describe how information behaves over a linear or multilinear channel. Information theory is always used to describe how information is communicated over a linear interval of time.

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