When cues are present at the encoding stage of the process but not present at retrieval stage then this is when forgetting may occur. Cues are like additional pieces of information that allow us to receive certain pieces of information we are seeking. You could suggest that this is a bit like the contents page of a book. These memory cues may be necessary to access information that is available but not accessible as certain chunks of information need these cues to be retrieved. There are two types of cues, the first is context which are environmental cues for example a classroom at school. An example in everyday life would be when someone goes upstairs to get something and forgets what it was, they might remember again when they are back downstairs in the same place that they first thought about it. The second is state which are cues internal to the person such as being excited or afraid. For example if you learn something when in a relaxed mood but cannot recall it when in a tense mood.

Cue-dependent forgetting can be supported by the fact that most people find that their recollections of childhood become less memorable as they get older. However, if they return to the place that they lived when they were a child, the streets, houses and school often serve to bring the past back to how they remembered. The physical environment of enfancy can act as an effective cue proving that many memory traces established a long time ago can be retrieved. The problem is we don't know what information is in the memory trace and which is extracted from the retrieval cue. So it may be difficult to know in some circumstances whether a true memory is accessed as a result of a cue or if the memory is a reconstruction. Baddeley argues the effects of context dependent forgetting only occur if the contexts in which information is learned and retrieved are vastly different. For example information learned in a classroom. and then retrieved in an ice rink will be poorer than if the same information had to be recalled in a library. Intereference theory would argue forgetting is due to confusion between old and new memories and not to do with the state of mind you are in. Cue dependent does not take biological factors for forgetting into account. Trace decay believes forgetting is due to the natural wasting away of the neural trace and therefore the context has little to do with forgetting. Has also been applied to real world successfully such as helping the police reconstructions based on cue dependency. The theory does have lots of experimental evidence to support it. Studies by Godden and Baddeley and/or Tulving and Pearlstone have demonstrated that forgetting is influenced by lack of retrieval cues present.