Personal Dev Study Systems¶
10 cards — 🟢 3 easy | 🟡 4 medium | 🔴 3 hard
🟢 Easy (3)¶
1. What is the basic principle behind spaced repetition and why does it work?
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Spaced repetition schedules reviews at increasing intervals: 1 day, then 3 days, then 7, then 21, etc. It works because it exploits the spacing effect — memory is strengthened more by spreading practice over time than by massing it together. Each review just before you would forget resets and extends the forgetting curve. The result: maximum retention with minimum total review time, because you only review when you need to.2. What is the Leitner box system and how does it implement spaced repetition without software?
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The Leitner system uses physical boxes (usually 3-5). New cards start in Box 1 (reviewed daily). Cards answered correctly move to the next box (reviewed less frequently). Cards answered incorrectly return to Box 1. Box 1: daily, Box 2: every 3 days, Box 3: weekly, Box 4: bi-weekly, Box 5: monthly. It implements spaced repetition mechanically — well-known cards automatically get reviewed less, struggling cards get reviewed more.3. What is retrieval practice and why is it more effective than re-reading?
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Retrieval practice is actively pulling information from memory (testing yourself) rather than passively reviewing it (re-reading notes). It is more effective because the act of retrieval itself strengthens the memory trace — struggling to recall builds stronger connections than recognizing familiar text. Research consistently shows that students who test themselves remember 50-80% more than students who re-read the same material for the same amount of time.🟡 Medium (4)¶
1. What is interleaving and why does it feel harder but produce better learning?
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Interleaving means mixing different topics or problem types within a single study session instead of practicing one type at a time (blocking). It feels harder because you cannot settle into a rhythm — each switch requires reloading context and selecting the right approach. This extra difficulty is precisely why it works: it forces discrimination between problem types, strengthens retrieval pathways, and builds transfer ability. Blocked practice creates an illusion of mastery that interleaving exposes.2. What is elaborative interrogation and when should you use it?
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Elaborative interrogation is asking "why?" and "how?" about facts you are learning and generating explanations in your own words. Instead of memorizing "TCP uses a three-way handshake," you ask "why does TCP need three steps instead of two?" and explain the reason. Use it when: (1) learning conceptual material (not just raw facts), (2) connecting new knowledge to existing knowledge, (3) building understanding that supports transfer to new situations. It is encoding that creates richer, more retrievable memory traces.3. What is dual coding theory and how do you apply it to studying?
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Dual coding (Allan Paivio) says information encoded in both verbal and visual forms creates two independent memory traces, making recall more likely — if one pathway fails, the other may succeed. Application: combine text notes with diagrams, flowcharts, or mental images. When studying a concept, create both a written explanation and a visual representation. The visual does not need to be artistic — a rough sketch of how components relate is sufficient. The act of translating between formats deepens encoding.4. What is desirable difficulty and how do you distinguish it from unproductive frustration?
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Desirable difficulty (Robert Bjork) is a learning condition that makes encoding harder in the short term but improves long-term retention and transfer. Examples: spacing, interleaving, retrieval practice, and generating answers before seeing them. It is desirable because the struggle strengthens memory. Unproductive frustration occurs when difficulty comes from poor materials, missing prerequisites, or unclear goals — the struggle does not build useful connections. The test: are you struggling with the content (desirable) or struggling with the process of accessing the content (undesirable)?🔴 Hard (3)¶
1. How does the SM-2 algorithm determine when to show a card next?
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SM-2 tracks three variables per card: ease factor (starting at 2.5), interval (days until next review), and consecutive correct count. After a correct answer (grade >= 3 out of 5): first correct = 1 day interval, second correct = 6 days, subsequent = previous interval x ease factor. Ease factor adjusts based on difficulty: easy recalls increase it, hard recalls decrease it (minimum 1.3). Any failure (grade < 3) resets the card to the beginning of the schedule. The algorithm personalizes each card's review frequency based on your performance history with that specific item.2. What is the testing effect and why does it challenge traditional study advice?
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The testing effect is the finding that being tested on material produces better long-term retention than additional study time on the same material — even when the test gives no feedback. It challenges traditional advice because students typically prefer re-reading and highlighting (which feel productive) over self-testing (which feels uncertain and harder). The testing effect shows that difficulty during study is not a sign of failure — it is the mechanism of learning. The discomfort of not knowing an answer IS the learning happening.3. What is the backlog death spiral in spaced repetition and how do you prevent or recover from it?