ls of memory coding. For this approach, structural-component stages such as STM and LTM, are not listed, instead these structures are described as processes such as pattern recognition and rehearsal. In this theory, an incoming stimulus can be processed in different ways, roughly divided into three broad domains, physical, acoustic, and semantic. Information can thus be processed first at a physical or perceptual level in terms of appearance. Second, it can be processed by acoustic properties or how it sounds. Third, it can be processed by the meaningful attributes (Klatzky, 1980).
These three types of processing can be ordered in terms of depth, with the physical form taking place at a more shallow level. This ordering resembles the three memory stores of the duplex model, with the sensory stores, acoustically coded STM, and meaningfully coded LTM. The levels theory focuses on deeper processing and better memory. A more accurate view of the memory system might include both models. The Duplex model offers a close look at short and long-term processing; the levels theory offers an expanded view of the active processing of stimulus items and relationships to long-term storage and retrieval, with its focus on meaningful processing or effective encoding into LTM (Klatzky, 1980).
Theories of forgetting include short-term memory forgetting. Forgetting is thought of as the result of either passive decay or interference. When an item is fresh and new, we can retrieve it readily, it is at its full strength. Item decay means that the information's strength decreases with the passage of time; since no other causal factor is specified, the decay is called passive. Interference refers to an active form of forgetting. In this case new items enter STM and their presence impairs recall for a given item. Displacement is a model that helps to clarify the general interference hypothesis; this simple slot idea states that forgettin...