What you'll learn
Memory is a fundamental cognitive process that allows us to retain and use information from past experiences. This revision guide covers the three key stages of memory: how information is converted into a form that can be stored (encoding), how it is maintained over time (storage), and how we access it when needed (retrieval). Understanding these processes is essential for WJEC GCSE Psychology and will prepare you for exam questions on memory failure, improvement techniques and real-world applications.
Key terms and definitions
Encoding — The process of converting sensory information into a form that can be stored in memory, through acoustic (sound), visual (image) or semantic (meaning) formats.
Storage — The retention of encoded information over time in short-term memory or long-term memory.
Retrieval — The process of accessing and bringing stored information from memory into conscious awareness.
Acoustic encoding — Storing information based on how it sounds; particularly important in short-term memory.
Semantic encoding — Storing information based on its meaning; the primary encoding method for long-term memory.
Capacity — The amount of information that can be held in a memory store at any one time.
Duration — The length of time information can be held in a memory store before it is lost.
Cue — A trigger or prompt that helps retrieve information from memory; can be internal (mood, context) or external (smell, place).
Core concepts
The three processes of memory
Memory operates through three interconnected stages that work together to allow us to form and use memories:
Encoding is the first stage where information from our environment enters the memory system. This can happen in three main ways:
- Acoustic encoding processes sound-based information (e.g., remembering a song lyric)
- Visual encoding processes what we see (e.g., recalling someone's face)
- Semantic encoding processes meaning (e.g., understanding and remembering a concept)
Research shows that deeper, more meaningful processing leads to better memory. When you actively think about what information means rather than just repeating it, you create stronger memory traces.
Storage maintains encoded information over periods ranging from seconds to a lifetime. The multi-store model identifies two main storage systems:
- Short-term memory (STM) holds limited information (7±2 items according to Miller, 1956) for brief periods (approximately 18-30 seconds without rehearsal)
- Long-term memory (LTM) has potentially unlimited capacity and can store information permanently
Retrieval accesses stored information when needed. This process can be influenced by various factors including the presence of retrieval cues and the context in which encoding originally occurred.
Encoding in different memory stores
Short-term memory primarily uses acoustic encoding. Peterson and Peterson (1959) demonstrated this by asking participants to remember consonant trigrams (e.g., XQF). When participants counted backwards to prevent rehearsal, recall dropped dramatically after just 18 seconds, showing STM's acoustic and time-limited nature.
Baddeley (1966) provided further evidence for acoustic encoding in STM. Participants found it harder to recall acoustically similar words (e.g., man, mad, cap, can) compared to acoustically dissimilar words, even when presented visually. This demonstrated that STM encodes information based on sound.
Long-term memory predominantly uses semantic encoding, focusing on meaning rather than sound or appearance. Baddeley (1966) showed that in LTM tasks, participants struggled with semantically similar words (e.g., large, big, huge, tall) but not acoustically similar ones. This proves we process meaning when storing information long-term.
Storage: capacity and duration
Short-term memory storage:
The capacity of STM is limited. Jacobs (1887) used the digit span technique, reading lists of numbers that participants had to recall immediately. On average, people could recall 7 digits, leading Miller (1956) to propose STM capacity is "seven plus or minus two" items (between 5-9 items).
Duration in STM is brief without rehearsal. Peterson and Peterson (1959) found that after 18 seconds of counting backwards (preventing rehearsal), participants recalled fewer than 10% of consonant trigrams correctly.
Long-term memory storage:
LTM has potentially unlimited capacity. Unlike STM, there's no evidence that LTM ever becomes "full" — we continue forming new memories throughout life.
Duration in LTM can be permanent. Bahrick et al. (1975) tested recall of classmates' names and faces from school yearbooks. Participants showed 90% accuracy for name recognition even 15 years after graduation, with 60% accuracy for free recall after 48 years. This demonstrates LTM's remarkable duration.
Retrieval and retrieval failure
Retrieval brings information from storage back into conscious awareness. Two main retrieval methods exist:
Recall requires retrieving information without prompts (e.g., "Name the three processes of memory"). This is more difficult than recognition.
Recognition involves identifying previously learned information when presented with it (e.g., multiple-choice questions). This is easier because the information serves as its own retrieval cue.
Retrieval cues are triggers that help access stored memories. Tulving (1974) proposed the encoding specificity principle: retrieval is most effective when cues present at encoding are also present at retrieval.
Context-dependent forgetting occurs when the physical environment differs between encoding and retrieval. Godden and Baddeley (1975) demonstrated this with divers who learned word lists either underwater or on land, then recalled them in the same or different environment. Recall was approximately 40% better when context matched.
State-dependent forgetting happens when internal state (mood, physical condition) differs between learning and recall. Goodwin et al. (1969) found that information learned while intoxicated was better recalled when intoxicated again, though this doesn't justify alcohol consumption — overall recall was worse in both conditions compared to sober learning.
Factors affecting encoding, storage and retrieval
Several factors influence how well the three processes work:
Rehearsal strengthens memory by repeating information. Maintenance rehearsal simply repeats information (keeping a phone number in mind), while elaborative rehearsal involves thinking about meaning and making connections, leading to better LTM encoding.
Organisation improves encoding and retrieval. Bower et al. (1969) showed participants who learned words in organised hierarchies (e.g., minerals → metals → rare metals → platinum) recalled nearly three times more than those learning randomly presented words.
Levels of processing (Craik and Lockhart, 1972) suggests deeper, more meaningful processing creates stronger memories. Shallow processing focuses on physical features (What font is this word in?), while deep processing considers meaning (Does this word fit in this sentence?). Deep processing produces superior recall.
Interference disrupts memory. Proactive interference occurs when old information blocks new information (e.g., calling your new teacher by your old teacher's name). Retroactive interference happens when new information disrupts old memories (e.g., learning Spanish after French and mixing up vocabulary).
Primacy and recency effects demonstrate serial position effects. In a list, people remember the first items (primacy effect — transferred to LTM through rehearsal) and last items (recency effect — still in STM) better than middle items. Murdock (1962) demonstrated this effect across numerous word list studies.
Worked examples
Example 1: Describe what is meant by 'encoding' (2 marks)
Mark scheme expectation: 1 mark for basic definition, 1 mark for elaboration/example.
Model answer: Encoding is the process of converting information into a form that can be stored in memory (1 mark). This can be done acoustically (based on sound), visually (based on appearance) or semantically (based on meaning) (1 mark).
Examiner tip: Define the term clearly in your first sentence, then expand with types or examples. Don't just repeat the question.
Example 2: Using your knowledge of retrieval, explain why a student might perform better in an exam held in their usual classroom compared to the school hall (4 marks)
Mark scheme expectation: Application of context-dependent forgetting/retrieval cues with clear explanation.
Model answer: The student would perform better in their usual classroom due to context-dependent retrieval (1 mark). This occurs when the physical environment at encoding (learning in the classroom) matches the environment at retrieval (taking the exam) (1 mark). The familiar surroundings act as retrieval cues that trigger memories formed in that same location (1 mark). When the exam is in the unfamiliar school hall, these environmental cues are absent, making it harder to access stored information (1 mark).
Examiner tip: The question asks you to "explain why" so you must go beyond description. Link the concept explicitly to the scenario provided and show cause-and-effect relationships.
Example 3: Outline one research study that investigated encoding in short-term memory (4 marks)
Mark scheme expectation: Procedure (2 marks) and findings (2 marks).
Model answer: Baddeley (1966) investigated encoding in STM by presenting participants with lists of words that were either acoustically similar (man, mad, cap, can) or acoustically dissimilar (1 mark). Participants were asked to recall the words immediately in the correct order (1 mark). Baddeley found that participants made more errors recalling the acoustically similar words compared to acoustically dissimilar words (1 mark). This demonstrated that STM primarily encodes information acoustically, as similar-sounding words caused confusion (1 mark).
Examiner tip: Structure research studies clearly: who conducted it, what they did (procedure), what they found (results), and what it showed (conclusion). Don't confuse studies — know the key details of each.
Common mistakes and how to avoid them
Confusing encoding types with memory stores. Acoustic encoding isn't the same as short-term memory — it's the primary method STM uses to encode, but it's the how not the where. STM is a store; acoustic encoding is a process.
Mixing up Peterson and Peterson with Baddeley. Peterson and Peterson tested STM duration (18 seconds), while Baddeley tested encoding types (acoustic vs semantic). Learn the specific findings of each study.
Describing retrieval failure without explaining the mechanism. Don't just say "they forgot because of context." Explain that matching contexts provide retrieval cues that trigger associated memories formed in that environment.
Using examples that don't demonstrate the concept. If asked about semantic encoding, don't describe remembering a phone number through repetition — that's acoustic/maintenance rehearsal. Use an example involving meaning, like remembering "photosynthesis" by understanding it means "putting together with light."
Confusing capacity with duration. Capacity is how much information fits; duration is how long it lasts. STM has limited capacity (7±2 items) AND short duration (18-30 seconds), but these are separate characteristics.
Writing about working memory or types of LTM unless specifically asked. Stick to the multi-store model's basic STM/LTM distinction for encoding, storage and retrieval questions unless the question explicitly mentions other models.
Exam technique for "Memory: Encoding, Storage and Retrieval"
Know your command words precisely. "Describe" requires you to write about something without explanation (typically 1 mark per point). "Explain" requires you to give reasons why something happens, showing understanding of cause-and-effect (usually 2 marks for point + explanation). "Outline a study" needs procedure AND findings.
Apply concepts to scenarios effectively. When questions present situations (student revising, witness recalling crime), explicitly link psychological concepts to the specific details given. Use phrases like "In this case..." or "This relates to... because..." to show application rather than just knowledge.
Structure research study answers using PFC. Procedure (what the researcher did), Findings (what results they got), Conclusion (what this showed about memory). This ensures you cover all mark scheme requirements without wasting words.
Plan answers to extended questions. For 6+ mark questions, spend 30-60 seconds planning. List 3-4 points you'll make, ensuring each is distinct. This prevents repetition and ensures balanced coverage across available marks.
Quick revision summary
Memory involves three processes: encoding (converting information into storable form through acoustic, visual or semantic methods), storage (retaining information in STM with limited capacity of 7±2 items and duration of 18-30 seconds, or LTM with unlimited capacity and potentially permanent duration), and retrieval (accessing stored information using recall or recognition). Encoding specificity explains why context and state-dependent cues aid retrieval. Baddeley demonstrated acoustic encoding in STM and semantic encoding in LTM. Peterson and Peterson showed STM's brief duration, while Bahrick proved LTM's longevity. Understanding these processes explains both memory success and failure.