Concept lists

1. Week 1:
   
   • Information Retrieval; Unstructured; Structured; semi-structured; Information need.
   • Term; Token; Document; Collection; Corpus.
   • Dictionary; Vocabulary; Lexicon.
   • Incidence matrix.
   • Inverted index; Postings; Postings list.
   • Query; Boolean retrieval model; Merge algorithm.
   • Ad hoc retrieval; Ranked query; Relevance; Effectiveness; Precision; Recall.
2. Week 2:
   
   • Stop words, stop list;
   • token normalization, equivalence classes;
   • case folding, truecasing;
   • stemming, porter stemmer;
   • lemmatization, lemma, lemmatizer;
   • skip list;
   • phrase queries, biword index, phrase index;
   • positional index.
   • binary tree, B-tree;
   • wildcard query, permuterm index, k-gram index;
   • edit distance, Levenshtern distance, dynamic programm, k-gram index filtering, Jaccard coefficient;
   • context sensitive spelling correction;
3. Week 3:
   
   • External sorting, blocked sort-based indexing (BSBI) algorithm, single-pass in-memory indexing;
   • MapReduce, key-value pairs;
   • Dynamic indexing, auxiliary index, logarithmic merging;
   • Rule of 30;
   • Lossless compression, lossy compression;
   • Heaps' law;
   • Zipf's law, power law;
   • Dictionary-as-a-string, blocked storage, front coding;
   • Variable byte encoding, continuation bit;
   • gamma codes, optimal gap encoding;
4. This is a growing list.