07.+Learning+&+Forgetting

March 3, 2015
 * 07. Learning & Forgetting**

Forgetting Applications
 * Outline**
 * Why we forget
 * How forgetting affects learning
 * Spacing for students and teachers
 * Testing for students and teachers

Jenkins & Dallenbach (1924): Subjects learn nonsense syllables and try to recall them up to 8 hours after learning, either:
 * Major theories of why we forget:**
 * Decay
 * Interference
 * Retrieval Failure
 * before they start the day
 * before they go to bed
 * Results: Subjects forgot much more after being awake than after sleep. Inconsistent with decay theory.

__Interference theory:__ similar memories interfere with each other. 2 types of interference:
 * Retroactive interference (RI)
 * New memories interfere with older memories
 * Proactive interference (PI)
 * Old memories interfere with new memories
 * Evidence for RI:
 * Tulving & Psotka (1971): Subjects study words to recall after a 20 minute delay
 * Half the subjects do math problems during the delay (minimal interference)
 * Half the subjects learn additional lists (lots of interference)
 * Results: Subjects doing math problems forgot almost nothing. Subjects learning additional lists forget a great deal.
 * Evidence for PI:
 * Wickens et al. (1976): Subjects learn lists across four trials.[[image:fruits.png width="309" height="264" align="right"]]
 * Trial 1-3
 * Fruits (control group)
 * Vegetables
 * Meats
 * Flowers
 * Occupations
 * Trial 4
 * Everyone saw the same list of 3 fruits
 * Results: recall of fruits on list 4 suffered when the initial topic was similar to fruits
 * Interference is a very powerful theory, much better than decay

__Retrieval Failure__
 * Tulving & Pearlstone (1966): Participants study list of 48 items (4 words/12 categories)
 * Half do free recall ("recall all the words you studied")
 * Half do cued recall ("recall the 4 fruits you studied")
 * Results:
 * Free recall: 40%
 * Cued recall: 62%
 * Free recall group recalled less than they had encoded.
 * Why do retrieval failures happen?
 * Cues fail to elicit targets
 * All retrieval is cued
 * Retrieval failure suggests memory has 2 dimensions:
 * Availability: Is it there?
 * Accessibility: Can you get it?
 * Learning is a function of accessibility
 * When accessibility is high, the benefit of studying is small.
 * Lower accessibility allows for more learning
 * Forgetting is the friend of learning

Benefits of forgetting:
 * Forgetting some memories is healthy (e.g., PTSD)
 * Older memories should be replaced with newer ones. For example, you don't need to remember where you parked your car four years ago.

Spaced vs. Massed studying Teaching
 * Applications**
 * Kornell (2009): Participants study 40 vocabulary word pairs (e.g., effulgent: brilliant)
 * Each item is studied 8 times, either all at once (small stacks) or across 4 sessions
 * Massed practice
 * Divide the flashcards into four stacks (5 cards each)
 * Study each stack on one of the four days (8 times that day)
 * Spaced practice
 * Keep the flashcards in a single stack (20 cards)
 * Study the same stack every day (2 times per day)
 * Spacing tested better
 * Why spacing practice is effective:[[image:curve.png width="375" height="216" align="right"]]
 * Accessibility
 * Spacing allows time for forgetting
 * Forgetting = a decrease in accessibility
 * Kornell (2009): Participants in massed condition thought they would do better, but ended up doing worse
 * [[image:predicted_v_actual.png]]
 * Why?
 * You do worse //while// you study (spaced)
 * Restudying after a delay means the information is less accessible (i.e., you forgot it)
 * Massing, by contrast, creates a false sense of knowledge
 * Desirable difficulties
 * Interventions that enhance learning by introducing difficulty during the learning process
 * Spacing decreases //performance// while studying
 * Yet spacing increases long-term learning
 * Rohrer & Taylor (2007)
 * Three sessions:
 * Week 1: Study
 * Week 2: Study
 * Week 3: Test
 * Two conditions during study
 * Mixers: all question types mixed
 * Blockers: one type of question at a time
 * [[image:practice.png width="261" height="320"]]
 * Two elements of problem solving (e.g., in physics)[[image:blockedmixed.png width="343" height="249" align="right"]]
 * Figure out what formulas (etc.) to use
 * Use them to solve problem
 * Massing makes the first element easy ("I'll just do what I did last time!")
 * Summary: Spacing
 * Spacing is a desirable difficulty
 * It enhances long-term learning
 * It impairs current performance

Another desirable difficulty: Retrieval
 * Roediger & Karpicke (2006):
 * Read one passage
 * Sea Otters
 * The Sun[[image:SSST.png align="right"]]
 * Two variables
 * Learning condition (S=study, T=test)
 * SSSS
 * SSST
 * STTT
 * Retention interval
 * 5 minutes
 * 1 week
 * SSSS did better in short term, RTTT did better in the long term
 * Summary of testing: tests enhance long-term learning

What if you get the wrong answer?
 * Study:
 * Read condition: Half of subjects are asked questions that have no right answer (so they must get them wrong), and then are shown the answer.
 * Pretest condition: Half of subjects are shown a question and an answer together
 * Results: Later, when tested, subjects who thought about and tried to retrieve the answer (even though they got it wrong) did better
 * Retrieval attempts enhance learning even if you don't think of the answer

Lyle & Crawford (2011): Two sections of a statistics course
 * Section 1: Standard lecture
 * Section 2: Teacher asked about 4 questions at the end about that day's lecture
 * Results: Section 2 did better--attempting retrieval improved their memory

Szpunar, Khan, & Schacter (2011): Participants viewed 21-minute online lectures. One group expected interpolated tests.
 * Expecting interim tests made people:
 * Take more notes
 * Mind-wander less
 * Learn more
 * Have less anxiety about the cumulative final

Haynie (1997): Undergraduate students in 6 technology education classes were provided a booklet on new "high-tech" materials developed for space exploration
 * 3 groups:
 * Group 1: Test announced, test given
 * Group 2: Test announced, no test given
 * Group 3: No test announced, no test given
 * Later: final criterion test
 * Results: Group 1 did better on delayed retention test