Interference | AQA A-Level Psychology Revision
Updated: Sep 9
For 7182 specification, first teach in September 2025
AQA A-Level Psychology | Free Revision Notes
Estimated study time: 40 minutes
These Interference A-Level Psychology revision notes explain how memories can compete and make one another more difficult to retrieve. You will learn the difference between proactive interference, where older information disrupts newer learning, and retroactive interference, where newer information disrupts older memories. Interference is most likely when the competing memories are similar. This lesson develops your understanding of forgetting beyond how information moves between memory stores and prepares you to distinguish interference from retrieval failure.
Learning Objectives 🎯
By the end of this revision page, you should be able to:
Define proactive interference.
Define retroactive interference.
Distinguish between the two forms of interference.
Explain how competing memories cause forgetting.
Explain why similarity increases interference.
Apply interference to unfamiliar examples of remembering and forgetting.
Revision Notes đź“š
What is interference?
Interference is an explanation of forgetting that occurs when two or more memories compete with one another.
The memories may be:
Similar in content.
Learned close together.
Associated with the same cue.
Required in the same situation.
Difficult to distinguish during retrieval.
Interference is mainly used to explain forgetting from long-term memory, or LTM.
The explanation proposes that information may have been stored but becomes difficult to recall because another memory disrupts access to it.
The two forms of interference are:
Proactive interference
Retroactive interference
Memory competition
Interference occurs because one memory becomes confused with or blocks access to another memory.
For example, imagine that you have recently changed your phone password.
You may:
Enter the old password when trying to remember the new one.
Become unsure whether a particular number belongs to the old or new password.
Remember parts of both passwords but combine them incorrectly.
Recall the newer password when trying to remember the old one.
The information has not necessarily disappeared. The problem is that the memories compete during retrieval.
Interference and the direction of disruption
The two types of interference are distinguished by the direction in which one memory affects another.
Type of interference | Direction of disruption |
Proactive interference | Older learning disrupts newer learning |
Retroactive interference | Newer learning disrupts older learning |
A useful starting point is:
Proactive:Â the past interferes with the present.Retroactive:Â recent learning reaches backwards.
These memory aids are helpful, but an examination definition must explain which information disrupts which.
Proactive interference
Definition of proactive interference
Proactive interference occurs when an older memory disrupts the recall of newer information.
The word proactive refers to the earlier learning acting forwards and interfering with something learned later.
The sequence is:
Information A is learned.
Information B is learned later.
Information A interferes with the recall of Information B.
This can be represented as:
Old learning → disrupts → new learning
Example of proactive interference
A person has used the password Swan47Â for several years. They change it to Swan74.
When signing in, they repeatedly enter the old password.
This is proactive interference because:
Swan47Â was learned first.
Swan74Â was learned later.
The old password interferes with recall of the new password.
Proactive interference in everyday life
Proactive interference may occur when someone:
Calls a new teacher by a previous teacher’s name.
Enters an old personal identification number instead of a new one.
Drives towards an old workplace after changing jobs.
Uses an old method after learning an updated procedure.
Writes a previous address on a form.
Uses vocabulary from a language learned earlier when speaking a newer language.
In each case, older knowledge disrupts access to information learned more recently.
Applying proactive interference
Mariam has moved house. When completing an online form, she automatically enters her previous postcode.
This can be explained by proactive interference because:
The previous postcode is the older memory.
The current postcode is the newer memory.
The well-established older information interferes with recall of the new postcode.
A weak application would say:
Mariam forgets because of proactive interference.
A stronger application identifies both memories and explains the direction of disruption:
Mariam’s old postcode was learned before her new postcode. The older information interferes with her ability to retrieve the newer postcode, demonstrating proactive interference.
Why older memories can be disruptive
Older information may be particularly likely to cause proactive interference when it has been:
Used many times.
Rehearsed extensively.
Stored for a long period.
Connected with a familiar response.
Frequently retrieved in the same situation.
For example, a password used daily for three years may be more established than a password created yesterday.
When the familiar cue appears, such as a login screen, the older response may be retrieved automatically.
Proactive interference and habits
Proactive interference can appear similar to the effect of habit.
A well-practised response may be triggered even though it is no longer correct.
For example, after a classroom changes, a student may continue walking towards the old room.
The old route has been repeatedly associated with the same lesson. It competes with the newly learned route.
The relevant principle is:
Previous learning remains strong and disrupts access to the replacement information.
Retroactive interference
Definition of retroactive interference
Retroactive interference occurs when newer information disrupts the recall of older information.
The word retroactive refers to the newer learning acting backwards and interfering with something learned previously.
The sequence is:
Information A is learned.
Information B is learned later.
Information B interferes with recall of Information A.
This can be represented as:
New learning → disrupts → old learning
Example of retroactive interference
A student learns a set of French vocabulary and later studies a similar set of Spanish vocabulary.
When asked to recall the French words, the newer Spanish words come to mind.
This is retroactive interference because:
The French words were learned first.
The Spanish words were learned afterwards.
The newer Spanish learning disrupts recall of the older French learning.
Retroactive interference in everyday life
Retroactive interference may occur when someone:
Learns a new telephone number and then struggles to recall the old one.
Learns a new route and becomes less able to describe the previous route.
Learns revised rules and forgets the original version.
Studies a new set of names and forgets names learned earlier.
Learns a new computer password and cannot remember the previous password.
Learns a new dance routine and confuses it with an earlier routine.
In each case, newer learning disrupts retrieval of information learned previously.
Applying retroactive interference
Jonah previously worked in Room 18 but now works in Room 81. After several weeks in the new room, he struggles to recall the number of his former room.
This may be explained by retroactive interference because:
Room 18 is the older memory.
Room 81 is the newer memory.
Learning the new room number interferes with retrieval of the former room number.
New learning does not erase the old memory
Retroactive interference does not necessarily mean that the newer memory destroys the older one.
The older information may still be stored but difficult to access because the newer memory competes with it.
For example, someone who cannot freely recall an old telephone number may recognise it when shown several possible numbers.
This suggests that the memory may remain available even when unaided recall is unsuccessful.
Comparing proactive and retroactive interference
Feature | Proactive interference | Retroactive interference |
Definition | Old learning disrupts recall of new learning | New learning disrupts recall of old learning |
Direction | Forwards in time | Backwards in time |
Competing memory | Earlier memory | Later memory |
Target memory | Newer memory | Older memory |
Password example | Old password prevents recall of the new password | New password prevents recall of the old password |
Language example | Previously learned French disrupts newly learned Spanish | Newly learned Spanish disrupts previously learned French |
One situation can involve both types
The same set of memories can produce both proactive and retroactive interference.
Imagine that someone changes their locker code from 426 to 462.
Entering 426 when trying to use the new code is proactive interference.
Being unable to remember 426 after learning 462 is retroactive interference.
The classification depends on:
Which information was learned first.
Which memory the person is currently trying to retrieve.
Which memory is causing the disruption.
A reliable method for identifying the type
Use these three questions:
What was learned first?
What was learned later?
Which memory is the person trying to recall?
Then decide:
If the old memory disrupts the new one, it is proactive.
If the new memory disrupts the old one, it is retroactive.
Worked classification example
Sam learned a colleague’s previous surname, Patel, before the colleague changed it to Parry.
Situation A
Sam tries to use the new surname but keeps saying Patel.
Old memory: Patel
New memory: Parry
Target: Parry
Disruption: Patel interferes with Parry
This is proactive interference.
Situation B
After using Parry for several years, Sam cannot recall the former surname.
Old memory: Patel
New memory: Parry
Target: Patel
Disruption: Parry interferes with Patel
This is retroactive interference.
How interference causes forgetting
Competing responses
Interference is likely when more than one response is connected to the same retrieval cue.
For example, the cue “online banking password” might activate:
The current password.
A previous password.
A password used for another account.
The individual must select the correct memory from several competing possibilities.
The greater the competition, the more difficult accurate retrieval may become.
Confusion between memories
Similar memories may become confused.
A person may:
Recall information from the wrong event.
Combine details from different memories.
Retrieve the wrong response.
Become uncertain which memory is correct.
Abandon an answer because several possibilities feel familiar.
For example, a student who has learned two similar psychological explanations may combine terminology from both.
This does not necessarily mean the student never learned the material. The two sets of knowledge may be competing.
Blocking retrieval
One memory may be retrieved so strongly that it blocks access to another memory.
For example, an old password may repeatedly enter conscious awareness, preventing the person from recalling the new one.
The unwanted memory acts as a competing response.
This links interference with the movement of information from long-term memory into conscious awareness.
Interference is not the same as decay
Decay would mean that a memory trace weakens because time passes.
Interference proposes that forgetting occurs because other information disrupts retrieval.
The difference is important:
Decay | Interference |
Forgetting is attributed to the passage of time | Forgetting is attributed to competing memories |
The memory trace is assumed to weaken | The memory may remain stored but difficult to retrieve |
Time itself is the key factor | The amount and similarity of intervening learning are key factors |
Interference research often attempts to separate the effect of elapsed time from the effect of new learning.
Interference is not the same as displacement
Displacement occurs when the limited capacity of short-term memory is exceeded and incoming information replaces existing information.
Interference is mainly an explanation of long-term forgetting involving competition between memories.
Displacement | Interference |
Associated with limited STM capacity | Mainly explains LTM forgetting |
Incoming items replace existing items | Stored memories compete during retrieval |
Concerns how much STM can hold | Concerns confusion between similar memories |
This distinction connects with capacity and duration in short-term memory.
Interference is not the same as retrieval failure
Interference and retrieval failure can both involve information being stored but temporarily inaccessible.
However, they explain the retrieval problem differently.
Interference | Retrieval failure |
Another memory disrupts access to the target | Suitable retrieval cues are absent |
Involves competition between memories | Involves a mismatch or lack of cues |
More likely when memories are similar | More likely when encoding and retrieval conditions differ |
Includes proactive and retroactive interference | Includes context-dependent and state-related forgetting |
The next lesson examines forgetting caused by an absence of cues.
The importance of similarity
Similar information creates more competition
Interference is more likely when the two memories are similar.
Similar memories may share:
The same subject matter.
Similar words.
Similar meanings.
A common context.
The same cue.
A similar response pattern.
For example, learning two lists of psychological terms may produce more interference than learning one list of terms followed by practising a visual-spatial task.
Why similarity matters
When memories are dissimilar, they are easier to distinguish.
For example:
A French vocabulary list and a set of dance movements are unlikely to be confused.
Two lists of French vocabulary contain similar material and may compete strongly.
Two phone numbers share the same format and may be retrieved in response to similar cues.
Two routes to the same destination may include overlapping roads and landmarks.
Similarity creates overlapping associations, making selection of the correct memory more difficult.
A simple relationship
The interference explanation predicts:
Greater similarity between memories → greater competition → greater forgetting
This does not mean that every similar memory will be forgotten. It means that similarity increases the likelihood of interference.
Similarity and proactive interference
Imagine that a student studied cognitive explanations of depression last week and cognitive explanations of obsessive-compulsive disorder this week.
The earlier material may intrude when the student tries to recall the newer explanation.
Because both topics involve cognitive concepts and specialist terminology, the memories may be difficult to separate.
This would be proactive interference because older learning disrupts the newer material.
Similarity and retroactive interference
The newer cognitive explanation may also make the student less able to recall the earlier one.
This would be retroactive interference because the later learning disrupts the older material.
Distinctive information reduces confusion
Memories may interfere less when they are:
Organised into clear categories.
Learned in different contexts.
Associated with distinctive cues.
Separated in time.
Understood rather than memorised as disconnected words.
Practised through active retrieval.
This does not remove interference completely, but it may help the learner distinguish between competing memories.
Research into similarity and interference
McGeoch and McDonald
Laboratory research by McGeoch and McDonald has been used to support the interference explanation.
Participants learned one set of material and then completed different intervening learning tasks before recalling the original information.
Recall was poorer when the intervening information was similar to the original material.
This supports interference because:
Forgetting varied according to the nature of the additional learning.
Similar material produced greater disruption.
Time alone cannot fully explain the pattern.
Competition between related memories provides a plausible explanation.
The key conclusion is not simply that participants forgot. It is that greater similarity produced greater interference.
Strength of controlled research
A strength of laboratory interference research is control.
Researchers can keep features consistent, including:
The amount of material.
The learning time.
The delay before recall.
The instructions.
The method of testing memory.
They can then change the type or similarity of the intervening material.
This makes it easier to investigate whether additional learning causes changes in recall.
Limitation of artificial material
Word lists and similar laboratory tasks may not represent meaningful everyday memories.
Participants may be asked to learn:
Unrelated words.
Artificial lists.
Material with little personal importance.
Several similar sets within a short period.
This may create more interference than people normally experience.
Everyday knowledge is often:
Meaningful.
Organised.
Connected to existing understanding.
Used in different contexts.
Rehearsed over longer periods.
Laboratory research may therefore demonstrate that interference can occur without showing how often it explains real-life forgetting.
Real-life evidence
Interference in rugby players’ memories
Research involving rugby players has examined memory for teams played during a season.
Some players had participated in more matches than others because injuries or other absences meant that not everyone played every game.
Recall became poorer when players had experienced more intervening matches.
This supports interference because the number of similar intervening events was important. The passage of time alone did not provide the best explanation.
The matches shared several features:
The same sport.
Similar rules.
Similar locations.
Overlapping teammates.
Similar sequences of play.
These similarities could cause memories of different matches to compete.
Why this evidence is valuable
Research involving real sporting experiences has greater everyday relevance than learning unrelated word lists.
The memories:
Developed naturally.
Were personally experienced.
Had genuine meaning.
Occurred over a realistic period.
Involved naturally varying amounts of intervening experience.
This supports interference as an explanation that can operate outside the laboratory.
Limitations of real-life research
Natural experiences are harder to control.
Rugby players may differ in:
How important each match was to them.
How often they discussed it.
Whether they scored or were injured.
Their attention during the match.
Their general memory ability.
The emotional significance of particular games.
These variables make it more difficult to conclude that interference alone caused the differences in recall.
Proactive interference in more detail
Build-up of proactive interference
Proactive interference may become stronger as more similar information is learned.
For example, remembering the latest of several hotel room numbers may become increasingly difficult because previous room numbers remain associated with the same cue.
The problem is not necessarily one single older memory. Several previous memories may compete with the new target.
Example involving names
A teacher learns the names of a new class after teaching several previous groups.
When trying to recall a new student’s name, the name of a similar-looking student from an earlier class comes to mind.
This is proactive interference because older names disrupt newer learning.
The interference may be increased because:
The cue is similar.
The setting is the same.
The teacher has learned many comparable name-face combinations.
Earlier associations are well established.
Example involving revision
A student revises explanations of conformity and later studies explanations of obedience.
When answering a question about obedience, the student writes about normative and informational social influence.
This may show proactive interference because earlier conformity material disrupts recall of the newer obedience content.
A strong examination application would identify:
The older learning.
The newer learning.
The target information.
The direction of interference.
Retroactive interference in more detail
Intervening learning
Retroactive interference depends on learning that occurs after the target memory was formed.
For example, a student learns one definition on Monday and a similar revised definition on Tuesday.
When asked for Monday’s definition, Tuesday’s version comes to mind.
The newer information is known as intervening learning because it occurs between the original learning and later recall.
Example involving procedures
A laboratory assistant learns Procedure A and uses it for several months. The organisation introduces Procedure B.
After repeatedly using Procedure B, the assistant struggles to describe the original procedure.
This may be retroactive interference because:
Procedure A was learned first.
Procedure B was learned later.
The newer procedure disrupts recall of the older one.
Example involving eyewitness memory
A witness remembers one version of an event but later receives new information about it.
If the later information disrupts recall of the original event, this could be described broadly as newer information interfering with an older memory.
However, questions about eyewitness testimony may focus specifically on leading questions and eyewitness testimony or post-event discussion. Use the explanation named in the question and avoid replacing eyewitness concepts with a generic interference account.
Interference and forgetting during revision
Studying similar topics together
Students may experience interference when they revise very similar topics close together.
Examples include:
Proactive and retroactive interference.
Compliance and internalisation.
The phonological loop and articulatory control process.
Context-dependent and state-related forgetting.
Similar studies with overlapping procedures.
The similarity can cause terms, findings and evaluation points to become confused.
Separating similar material
Possible strategies include:
Comparing the concepts directly in a table.
Using different examples for each explanation.
Practising retrieval rather than only rereading.
Leaving a gap between highly similar topics.
Using headings that identify the exact target question.
Explaining the difference aloud.
Creating distinct cues for each concept.
These strategies are applications of the interference explanation rather than guarantees against forgetting.
Interleaving and interference
Mixing topics can strengthen discrimination when the learner actively compares them.
However, rapidly reading several similar sections without retrieval or comparison may create confusion.
The important difference is whether the learner:
Passively encounters overlapping information.
Or actively practises distinguishing between the concepts.
For example, answering mixed questions on proactive and retroactive interference may help because the student repeatedly decides which definition applies.
Expertise may reduce interference
People with strong subject knowledge may organise information into clear categories.
An expert may distinguish between similar memories using:
Detailed schemas.
Specialist cues.
Strong conceptual understanding.
Knowledge of meaningful differences.
Extensive retrieval practice.
This may reduce confusion.
Interference does not therefore affect every person or every memory equally.
Does interference erase memories?
Evidence that cues can improve recall
Research has found that recall affected by interference may improve when suitable cues are provided.
This suggests that the original information may not have been destroyed.
Instead:
The memory remains stored.
Competing information makes unaided retrieval difficult.
A cue helps identify the correct target.
Recall improves.
This creates an overlap between interference and retrieval-based explanations of forgetting.
Accessibility rather than availability
A useful distinction is between:
Availability, whether the memory is stored.
Accessibility, whether it can be retrieved at that moment.
Interference may reduce accessibility without eliminating availability.
For example, someone may fail to recall an old colleague’s surname but recognise it when shown a list.
The old memory remains available, but newer names may have interfered with free recall.
Implication for the explanation
If a cue restores the memory, it is difficult to argue that the information has been permanently lost.
Interference may therefore be better understood as a temporary retrieval problem in some situations.
This does not disprove the explanation. It clarifies the process through which competing memories affect recall.
Evaluating interference as an explanation
Research supports interference
A strength of the explanation is evidence showing that additional learning can reduce recall.
Laboratory studies demonstrate that:
Intervening material can disrupt memory.
Similar material produces greater forgetting.
The type of intervening information matters.
Real-life research also indicates that multiple similar experiences can make earlier events more difficult to remember.
Together, this evidence supports the idea that memories can compete.
Similarity provides a clear prediction
The explanation predicts that interference should become stronger when memories are more alike.
This is useful because it can be tested.
Researchers can compare recall after participants learn:
Similar material.
Dissimilar material.
No intervening material.
If recall is poorest after similar learning, the result supports the explanation.
Controlled research may exaggerate interference
Laboratory studies often require participants to learn highly similar material in a short period.
This is almost designed to create interference.
In everyday life, memories may be more distinctive and separated by:
Different contexts.
Personal meaning.
Longer time intervals.
Different purposes.
More varied retrieval cues.
The research may therefore overestimate how often interference causes ordinary forgetting.
Real-life evidence improves validity
Studies of naturally occurring memories, such as memories for sporting events, support the explanation outside controlled word-list tasks.
This increases ecological validity because the memories are meaningful and develop through genuine experiences.
However, the reduced control means that other variables may contribute to forgetting.
Interference may be temporary
The finding that cues can restore recall suggests that interference does not necessarily erase memories.
The target may remain in LTM but be blocked by competing information.
This limits any claim that interference permanently removes a memory.
It also suggests that retrieval cues and encoding conditions may sometimes provide a more complete explanation.
Interference does not explain all forgetting
People forget information even when there is little similar competing material.
For example, forgetting may occur because:
Suitable retrieval cues are absent.
Information was not encoded effectively.
Attention was limited.
The memory was weakly organised.
The person misunderstood the material.
Interference is therefore one explanation of forgetting rather than a complete account.
Individual differences
Not everyone experiences the same amount of interference.
The effect may depend on:
Expertise.
Familiarity.
Organisation of knowledge.
The meaningfulness of information.
Retrieval strategies.
The strength of the original memory.
This means interference is not determined by similarity alone.
Practical usefulness
Interference has useful applications to learning and revision.
It suggests that students may benefit from:
Making similar topics distinctive.
Practising differences explicitly.
Avoiding long sequences of nearly identical material.
Using retrieval cues.
Revisiting earlier learning after studying new content.
Checking whether new learning has disrupted old knowledge.
An explanation with practical applications can be valuable even if it does not account for every case of forgetting.
Applying interference to unfamiliar situations
A four-stage application structure
Use the following structure:
Identify the type of interference.
State which information was learned first.
State which information was learned later.
Explain which memory disrupts the target memory.
Proactive application template
This is proactive interference because the older memory of ______ disrupts the person’s recall of the newer ______.
Retroactive application template
This is retroactive interference because the newer memory of ______ disrupts the person’s recall of the older ______.
Example with two languages
Sofia learned German last year and began learning Dutch this year. When speaking Dutch, German words repeatedly come to mind.
This is proactive interference because:
German was learned first.
Dutch was learned later.
Sofia is trying to retrieve Dutch.
Older German vocabulary disrupts the newer Dutch vocabulary.
If Sofia later struggles to recall German because Dutch words come to mind, this would be retroactive interference.
Example with a changed timetable
A student used Timetable A for several months and then received Timetable B.
Following Timetable A instead of B is proactive interference.
Forgetting the details of A after learning B is retroactive interference.
Example with research studies
A psychology student learns the procedure of Study A and later learns a similar Study B.
During an examination on Study A, they write the participant details from Study B.
This is retroactive interference because newer learning about Study B disrupts recall of the older Study A.
Avoiding circular explanations
A weak answer states:
The student forgets because the memories interfere.
This simply repeats the name of the explanation.
A developed answer states:
The two studies contain similar procedures, so both memories are activated by the examination question. Details from the newer study compete with and disrupt retrieval of the older study, producing retroactive interference.
Hints from the Examiner Reports đź’ˇ
Examiner hint:Â Distinguish the direction of interference clearly. Proactive interference involves old information disrupting new learning, whereas retroactive interference involves new information disrupting older learning.
Examiner hint:Â Use research as evidence rather than as an isolated description. Explain how poorer recall following similar intervening material supports interference.
Examiner hint:Â Strong evaluation can include both controlled laboratory evidence and real-life research involving meaningful memories.
Examiner hint:Â Generic criticism of a study is not enough. If you argue that word-list research is artificial, explain why this may exaggerate interference compared with organised everyday memories.
Examiner hint:Â Contradictory findings should be linked directly to the explanation. Evidence that cues restore recall suggests that interference may block accessibility rather than erase the memory.
Examiner hint:Â Alternative explanations, such as retrieval failure caused by absent cues, should be used to assess whether interference provides a complete explanation of forgetting.
Examiner hint:Â Avoid lengthy descriptions that do not answer the question. In an evaluation response, select the finding and explain what it tells us about interference.
Examiner hint: Use specialist terms such as proactive interference, retroactive interference, similarity, intervening learning and retrieval accurately.
Common Mistakes ⚠️
Mistake: Reversing proactive and retroactive interference
Why this is incorrect:
The two explanations differ according to which memory causes the disruption.
How to improve:
Remember:
Proactive: old disrupts new.
Retroactive: new disrupts old.
Mistake: Defining proactive interference as “forgetting old information”
Why this is incorrect:
Proactive interference affects the newer target memory.
How to improve:
State that older learning disrupts recall of newer information.
Mistake: Defining retroactive interference as “forgetting new information”
Why this is incorrect:
Retroactive interference affects the older target memory.
How to improve:
State that newer learning disrupts recall of previously learned information.
Mistake: Identifying only one memory
Why this is incorrect:
Interference requires at least two competing memories.
How to improve:
Name both the old and new information and explain their relationship.
Mistake: Ignoring the target memory
Why this is incorrect:
The same two memories can produce either form of interference depending on which one the person is trying to retrieve.
How to improve:
Identify the information the person currently needs.
Mistake: Saying that interference is caused only by time
Why this is incorrect:
Interference focuses on learning or experiences occurring during the interval, particularly similar information.
How to improve:
Refer to the competing material rather than elapsed time alone.
Mistake: Assuming that interference destroys the memory
Why this is incorrect:
The memory may remain stored but be difficult to access.
How to improve:
Explain that competing information can block or confuse retrieval.
Mistake: Forgetting the role of similarity
Why this is incorrect:
Interference is more likely when memories overlap or share cues.
How to improve:
Explain why similar information is difficult to distinguish.
Mistake: Confusing interference with displacement
Why this is incorrect:
Displacement concerns information being replaced within limited-capacity STM. Interference mainly concerns competition between memories in LTM.
How to improve:
Identify whether the question concerns capacity or competition during retrieval.
Mistake: Giving a generic laboratory criticism
Why this is incorrect:
Saying that a study is artificial does not explain the effect on interference theory.
How to improve:
State that learning several similar word lists may create more interference than meaningful, well-organised memories in everyday life.
Mistake: Describing research without reaching a conclusion
Why this is incorrect:
Research procedure alone does not evaluate an explanation.
How to improve:
Complete the link:
Poorer recall following similar intervening learning supports the claim that similarity increases memory competition.
Exam-Style Questions ✍️
Question 1
Which one of the following correctly describes proactive interference?
A. New learning disrupts recall of old learning
B. Old learning disrupts recall of new learning
C. A memory fades because time passes
D. A cue is absent during retrieval
[1 mark]
reveal mark scheme and indicative content
Answer: B. Old learning disrupts recall of new learning
Question 2
Define proactive interference.
[2 marks]
reveal mark scheme and indicative content
Mark scheme
AO1 = 2
2 marks:Â Clear definition stating that older learning disrupts the recall of newer learning.
1 mark:Â Limited or partial definition.
Example answer
Proactive interference occurs when information learned previously interferes with the recall of more recently learned information.
Question 3
Define retroactive interference.
[2 marks]
reveal mark scheme and indicative content
Mark scheme
AO1 = 2
2 marks:Â Clear definition stating that newer learning disrupts the recall of older learning.
1 mark:Â Limited or partial definition.
Example answer
Retroactive interference occurs when newly learned information interferes with the recall of information learned previously.
Question 4
Explain one difference between proactive interference and retroactive interference.
[3 marks]
reveal mark scheme and indicative content
Mark scheme
AO1 = 3
1 mark:Â Proactive interference involves older information disrupting newer information.
1 mark:Â Retroactive interference involves newer information disrupting older information.
1 mark:Â Clear comparison or appropriate example demonstrating the direction of interference.
Example answer
In proactive interference, an older memory disrupts the recall of newer information. In retroactive interference, the direction is reversed, so newer learning disrupts the recall of information learned earlier.
Question 5
For several years, Imran used the password River56. He recently changed it to River65, but he repeatedly enters the previous password.
Use your knowledge of interference to explain Imran’s behaviour.
[4 marks]
reveal mark scheme and indicative content
Mark scheme
AO2 = 4
Award 1 mark each for:
Identifying proactive interference.
River56 is the older, previously learned password.
The old password interferes with recall of the newer River65 password.
The similarity between the two passwords increases interference or response competition.
Example answer
Imran is experiencing proactive interference because his old password, River56, is disrupting recall of his new password, River65. The passwords are very similar, so they compete with each other in memory, making it more likely that he will enter the old password.
Question 6
Aisha learned a set of Italian vocabulary in September. In October, she learned a similar set of Spanish vocabulary. When tested on the Italian words, she frequently gives Spanish answers.
Explain Aisha’s forgetting using interference.
[4 marks]
reveal mark scheme and indicative content
Mark scheme
AO2 = 4
Award 1 mark each for:
Identifying retroactive interference.
The Italian vocabulary is the older learning.
The newer Spanish vocabulary disrupts recall of the Italian words.
Similarity between the two sets of vocabulary increases interference or response competition.
AQA specifically recognises that interference is more likely when the two sets of material are similar.
Example answer
Aisha is experiencing retroactive interference because the Spanish vocabulary learned later is disrupting her memory for the Italian vocabulary learned earlier. Because both sets contain similar material, they may become confused and compete during retrieval, causing her to give Spanish rather than Italian answers.
Question 7
A researcher asked participants to learn a list of 12 words. Participants then completed one of four activities before recalling the original list.
Intervening activity | Mean number of original words recalled |
Learned a list of words with similar meanings | 3.4 |
Learned a list of unrelated words | 6.8 |
Completed a number task | 8.1 |
Completed no intervening task | 9.0 |
Describe the pattern shown in the results. Use interference to explain why recall differed between the conditions.
[6 marks]
reveal mark scheme and indicative content
Mark scheme
AO2 = 6
Award up to 3 marks for describing the pattern and 3 marks for explaining it.
Indicative content
Pattern
Recall is lowest after learning words with similar meanings, 3.4.
Recall is higher after unrelated words, 6.8, and a number task, 8.1.
Recall is highest with no intervening task, 9.0.
Explanation
Learning new words after the original list produces retroactive interference.
Interference is strongest when the new and old material is similar because this creates greater response competition.
The number task produces less interference because it is less similar to the original verbal material, while no intervening task produces the least interference.
Example answer
Recall is lowest after participants learn words with similar meanings, at 3.4, compared with 6.8 after unrelated words, 8.1 after a number task and 9.0 with no intervening task. Learning the second word list causes retroactive interference because new learning disrupts recall of the original list. The effect is strongest when the two lists are similar because similar memories compete more strongly with one another.
AQA has previously awarded credit for retroactive interference where newly learned, similar material disrupts recall of an earlier list
Question 8
Leila has worked in three different laboratories. Each laboratory uses a similar but slightly different safety procedure. During training at her newest workplace, she repeatedly describes the procedure used in her first laboratory. Several months later, she struggles to remember the original procedure because the newer procedures come to mind.
Explain both examples with reference to proactive and retroactive interference.
[6 marks]
reveal mark scheme and indicative content
Mark scheme
AO2 = 6
Award up to 3 marks for proactive interference and 3 marks for retroactive interference.
Proactive interference
During training at the newest laboratory, the earlier procedure interferes with learning or recalling the new procedure.
The procedure from the first laboratory is older learning.
Similarity between the procedures makes proactive interference more likely.
Retroactive interference
Several months later, the newer procedures interfere with recall of the original procedure.
The new procedures have been learned after the original one.
Their similarity creates response competition and makes the original procedure more difficult to retrieve.
Example answer
During training, Leila experiences proactive interference because the procedure learned in her first laboratory interferes with the newer procedure she is trying to learn. This is especially likely because the procedures are similar. Later, she experiences retroactive interference because the procedures learned in the newer laboratories disrupt her recall of the original procedure. The similar procedures compete with one another in memory, causing confusion.
Question 9
Outline one strength and one limitation of interference as an explanation for forgetting.
[6 marks]
reveal mark scheme and indicative content
Mark scheme
AO3 = 6
Award up to 3 marks for the strength and 3 marks for the limitation.
Indicative content
Strength
There is research support for interference.
For example, McGeoch and McDonald found that forgetting was greater when subsequently learned material was similar to the original material.
This supports the prediction that similarity increases interference and response competition.
Limitation
Much interference research uses artificial materials such as lists of unrelated words.
Interference is often deliberately created by asking participants to learn similar material in a short period.
This may not reflect how memories are learned and forgotten in everyday life, reducing ecological validity.
AQA's 2025 mark scheme explicitly accepts laboratory evidence such as McGeoch and McDonald as support, while previous AQA marking guidance recognises the artificial materials and deliberate induction of interference as limitations. Â
Example answer
One strength is research support. McGeoch and McDonald found greater forgetting when participants learned new material that was similar to the original material. This supports the interference explanation because it predicts that similar memories will compete more strongly.
One limitation is that many studies use artificial tasks such as learning lists of words and deliberately create interference. This may not represent the way forgetting normally occurs in everyday life, reducing the ecological validity of the explanation.
Question 10
Discuss interference as an explanation for forgetting. Refer to proactive and retroactive interference in your answer.
[16 marks]
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