When two lots of information became confused in memory
Interference
More likely when the material is similar as it creates response competition
Proactive interference
Old learning affects recall of new information e.g. putting in your old password after you've changed it. The newer information is forgotten.
Retroactive interference
A newer memory disrupts an older memory e.g. after learning your new mobile number, you can't remember your old one. The older information is forgotten.
Interference is less likely to occur when there is a gap between the instances of learning
McGeach and McDonald studied retroactive interference
