A love letter to flashcards

Original Article ↗ Hacker News Discussion ↗

Flashcards and spaced repetition tools like Anki are praised as powerful aids for retaining everything from foreign vocabulary and medical facts to math definitions, chess patterns, and command-line syntax, especially when time and attention are fragmented. Commenters argue that their real value comes from active recall, chunking, and personally crafted cards, while warning that memorization alone can’t replace deeper practice such as solving problems, writing proofs, or engaging with native-language input. There is cautious optimism about using AI to help generate or vary cards, but many find that automation often produces generic, context-poor material and that motivation and consistency ultimately matter more than any specific app or algorithm.

Use in Conceptual Domains (Math, Science, Chess, etc.)

  • Several commenters use spaced repetition for higher math: especially memorizing definitions, lemmas, theorems, and representative problems.
  • Some report that knowing all definitions/theorems by heart helped on exams, but they still struggled with proofs due to insufficient practice applying the knowledge.
  • Others argue that if you need flashcards for basic definitions in analysis/group theory, you probably haven’t solved enough problems; repeated use can implicitly provide “spaced repetition.”
  • For math/physics, suggestions include: break theorems into multiple cards, use problem-style cards that require solving, and keep a separate deck for time‑intensive “solve this” cards.
  • Chess is learned via position images (tactics, endgames, openings) with the best move as the answer, updated periodically as rating changes.

Memorization vs Understanding

  • One camp sees SRS as “drills” or foundation: essential for rapid recall of facts and procedures, on top of which understanding is built.
  • Another camp worries that flashcards encourage shallow, test‑oriented learning and underweight conceptual mapping and mental models.
  • Some counter that memorization and understanding are not either-or: memorizing even partially understood material can create a scaffold for later comprehension.
  • Chunking and procedural fluency (e.g., being able to write code or do math without prompts) are cited as major benefits of active recall.

Language Learning Debates

  • Heavy use of Anki for vocab is common; many report dramatic gains in retention compared to “natural” study.
  • Others find naive word lists with translations inefficient and advocate sentence mining with rich context, often via cloze deletion cards.
  • There’s disagreement on whether sentence cards are more or less efficient than single-word cards, and whether AI-generated sentences are good enough.
  • Multiple commenters stress that SRS can’t replace large amounts of listening/reading, especially for listening comprehension and advanced nuance.

Tools, Algorithms, and Custom Systems

  • Some praise Anki’s newer scheduling and flexibility; others prefer Leitner or write small custom SRS programs (often using open-source FSRS libraries).
  • People repurpose flashcards for CLI commands, business facts, Emacs shortcuts, mental arithmetic, GTD-style reminders, and conceptual mapping tools.

LLMs and Automatic Card Generation

  • Simple “paste a chapter, ask for cards” approaches are widely seen as producing impersonal, low‑value decks that still need heavy editing.
  • More elaborate pipelines (tools, validation passes, AnkiConnect integration) reportedly yield high‑quality automated cards and reduce creation friction.
  • Concerns remain that AI‑ or shared decks lose the personal context and cognitive work that make self-written cards powerful.

Motivation, Friction, and Limits

  • Many find daily SRS hugely helpful mainly because it enforces consistency; others abandon it because reviews are aversive or feel like a chore.
  • Some argue flashcard work need not be “fun,” only effective; others say if it feels dreadful, learners will quit, so card design and workload must be tuned.
  • Flashcards are seen as excellent for certain goals (terminology-heavy fields, large vocabularies, factual scaffolding) but limited for skills requiring deep fluency, creativity, or rich, contextual understanding unless combined with other practice.