Cue-dependent forgetting

Cue-dependent forgetting, or retrieval failure, is the failure to recall a memory due to missing stimuli or cues that were present at the time the memory was encoded. It is one of five cognitive psychology theories of forgetting. It states that a memory is sometimes temporarily forgotten purely because it cannot be retrieved, but the proper cue can bring it to mind. A good metaphor for this is searching for a book in a library without the reference number, title, author or even subject. The information still exists, but without these cues retrieval is unlikely. Furthermore, a good retrieval cue must be consistent with the original encoding of the information. If the sound of the word is emphasized during the encoding process, the cue that should be used should also put emphasis on the phonetic quality of the word (Psychology Themes and variations, pg 282).

State-Dependent Cues
State-dependent cues are governed by the state of mind and being at the time of encoding. Memory retrieval can be facilitated or triggered by replication of an emotional or mental state, such as being inebriated, drugged, upset, anxious, happy, or in love.

Context-Dependent Cues
Context-dependent cues are dependent on the environment and situation. Memory retrieval can be facilitated or triggered by replication of the context in which the memory was encoded. Such conditions include weather, company, location, smelling a particular odor, or hearing a certain phrase. For example, students sometimes fail to recall diligently studied material when an examination room's environmental conditions differ significantly from the room or place where learning occurred. To improve learning and recall, it is recommended that students should study under conditions that closely resemble an examination.