Science & Linguistics
Glossary & Knowledge Base.
The authoritative reference manual for evidence-based language acquisition, active recall retrieval mechanics, and modern 17-parameter spaced repetition.
Spaced Repetition System (SRS)
An evidence-based learning technique that schedules reviews of flashcards at increasing intervals to exploit the psychological spacing effect.
Cloze Deletion Test
An active recall language drill where targeted words or morphemes are excised from a complete sentence, requiring the learner to produce the exact missing token.
Active Recall (Testing Effect)
The cognitive principle that actively retrieving information from memory produces stronger and more durable neural pathways than passive re-exposure.
Comprehensible Input (i+1 Hypothesis)
Stephen Krashen's second-language acquisition hypothesis stating that language is acquired when learners receive messages they understand with one step beyond their current level.
CEFR Proficiency Framework (A1–C2)
The Common European Framework of Reference for Languages—an international standard describing language proficiency across six structured tiers.
Ebbinghaus Forgetting Curve
The mathematical model showing how newly learned information is rapidly lost over time when no attempt is made to retain it.
Collocation & Lexical Chunking
The principle that words naturally co-occur in habitual chunks (e.g. 'make a decision' vs 'do a decision'), requiring sentence-level acquisition.
Interleaving Practice Effect
A learning technique where different topics, grammar tenses, or skills are mixed together during practice rather than drilled in blocked batches.
The Testing Effect (Retrieval Practice)
The finding that taking a memory test produces greater long-term learning than spending the same amount of time restudying.
Affective Filter Hypothesis
Krashen's model showing that emotional variables such as anxiety, self-confidence, and motivation act as a mental filter that can block language acquisition.
Lexical Frequency & Zipf's Law
The mathematical distribution of vocabulary where the top 1,000 words account for 85% of all spoken discourse in any natural language.
Pimsleur Graduated Interval Recall
An early audio-based spaced repetition schedule proposing intervals of 5 seconds, 25 seconds, 2 minutes, 10 minutes, 5 hours, and so forth.
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