This book presents the latest research in cognitive psychology which is a school of thought in psychology that examines internal mental processes such as problem solving, memory, and language. The school of thought arising from this approach is known as cognitivism. Cognitive psychologists are interested in how people understand, diagnose, and solve problems, concerning themselves with the mental processes which mediate between stimulus and response. Cognitive theory contends that solutions to problems take the form of algorithms -- rules that are not necessarily understood but promise a solution, or heuristics -- rules that are understood but that do not always guarantee solutions. In other instances, solutions may be found through insight, a sudden awareness of relationships.