Contents

• List of Tables
• List of Figures
• Boolean retrieval
  • An example information retrieval problem
  • A first take at building an inverted index
  • Processing Boolean queries
  • The extended Boolean model versus ranked retrieval
  • References and further reading
  
  
• The term vocabulary and postings lists
  • Document delineation and character sequence decoding
    • Obtaining the character sequence in a document
    • Choosing a document unit
  • Determining the vocabulary of terms
    • Tokenization
    • Dropping common terms: stop words
    • Normalization (equivalence classing of terms)
    • Stemming and lemmatization
  • Faster postings list intersection via skip pointers
  • Positional postings and phrase queries
    • Biword indexes
    • Positional indexes
    • Combination schemes
  • References and further reading
  
  
• Dictionaries and tolerant retrieval
  • Search structures for dictionaries
  • Wildcard queries
    • General wildcard queries
    • k-gram indexes for wildcard queries
  • Spelling correction
    • Implementing spelling correction
    • Forms of spelling correction
    • Edit distance
    • k-gram indexes for spelling correction
    • Context sensitive spelling correction
  • Phonetic correction
  • References and further reading
  
  
• Index construction
  • Hardware basics
  • Blocked sort-based indexing
  • Single-pass in-memory indexing
  • Distributed indexing
  • Dynamic indexing
  • Other types of indexes
  • References and further reading
  
  
• Index compression
  • Statistical properties of terms in information retrieval
    • Heaps' law: Estimating the number of terms
    • Zipf's law: Modeling the distribution of terms
  • Dictionary compression
    • Dictionary as a string
    • Blocked storage
  • Postings file compression
    • Variable byte codes
    • Gamma codes
  • References and further reading
  
  
• Scoring, term weighting and the vector space model
  • Parametric and zone indexes
    • Weighted zone scoring
    • Learning weights
    • The optimal weight g
  • Term frequency and weighting
    • Inverse document frequency
    • Tf-idf weighting
  • The vector space model for scoring
    • Dot products
    • Queries as vectors
    • Computing vector scores
  • Variant tf-idf functions
    • Sublinear tf scaling
    • Maximum tf normalization
    • Document and query weighting schemes
    • Pivoted normalized document length
  • References and further reading
  
  
• Computing scores in a complete search system
  • Efficient scoring and ranking
    • Inexact top K document retrieval
    • Index elimination
    • Champion lists
    • Static quality scores and ordering
    • Impact ordering
    • Cluster pruning
  • Components of an information retrieval system
    • Tiered indexes
    • Query-term proximity
    • Designing parsing and scoring functions
    • Putting it all together
  • Vector space scoring and query operator interaction
  • References and further reading
  
  
• Evaluation in information retrieval
  • Information retrieval system evaluation
  • Standard test collections
  • Evaluation of unranked retrieval sets
  • Evaluation of ranked retrieval results
  • Assessing relevance
    • Critiques and justifications of the concept of relevance
  • A broader perspective: System quality and user utility
    • System issues
    • User utility
    • Refining a deployed system
  • Results snippets
  • References and further reading
  
  
• Relevance feedback and query expansion
  • Relevance feedback and pseudo relevance feedback
    • The Rocchio algorithm for relevance feedback
    • Probabilistic relevance feedback
    • When does relevance feedback work?
    • Relevance feedback on the web
    • Evaluation of relevance feedback strategies
    • Pseudo relevance feedback
    • Indirect relevance feedback
    • Summary
  • Global methods for query reformulation
    • Vocabulary tools for query reformulation
    • Query expansion
    • Automatic thesaurus generation
  • References and further reading
  
  
• XML retrieval
  • Basic XML concepts
  • Challenges in XML retrieval
  • A vector space model for XML retrieval
  • Evaluation of XML retrieval
  • Text-centric vs. data-centric XML retrieval
  • References and further reading
  • Exercises
  
  
• Probabilistic information retrieval
  • Review of basic probability theory
  • The Probability Ranking Principle
    • The 1/0 loss case
    • The PRP with retrieval costs
  • The Binary Independence Model
    • Deriving a ranking function for query terms
    • Probability estimates in theory
    • Probability estimates in practice
    • Probabilistic approaches to relevance feedback
  • An appraisal and some extensions
    • An appraisal of probabilistic models
    • Tree-structured dependencies between terms
    • Okapi BM25: a non-binary model
    • Bayesian network approaches to IR
  • References and further reading
  
  
• Language models for information retrieval
  • Language models
    • Finite automata and language models
    • Types of language models
    • Multinomial distributions over words
  • The query likelihood model
    • Using query likelihood language models in IR
    • Estimating the query generation probability
    • Ponte and Croft's Experiments
  • Language modeling versus other approaches in IR
  • Extended language modeling approaches
  • References and further reading
  
  
• Text classification and Naive Bayes
  • The text classification problem
  • Naive Bayes text classification
    • Relation to multinomial unigram language model
  • The Bernoulli model
  • Properties of Naive Bayes
    • A variant of the multinomial model
  • Feature selection
    • Mutual information
    • $\chi ^2$ Feature selectionChi2 Feature selection
    • Frequency-based feature selection
    • Feature selection for multiple classifiers
    • Comparison of feature selection methods
  • Evaluation of text classification
  • References and further reading
  
  
• Vector space classification
  • Document representations and measures of relatedness in vector spaces
  • Rocchio classification
  • k nearest neighbor
    • Time complexity and optimality of kNN
  • Linear versus nonlinear classifiers
  • Classification with more than two classes
  • The bias-variance tradeoff
  • References and further reading
  • Exercises
  
  
• Support vector machines and machine learning on documents
  • Support vector machines: The linearly separable case
  • Extensions to the SVM model
    • Soft margin classification
    • Multiclass SVMs
    • Nonlinear SVMs
    • Experimental results
  • Issues in the classification of text documents
    • Choosing what kind of classifier to use
    • Improving classifier performance
  • Machine learning methods in ad hoc information retrieval
    • A simple example of machine-learned scoring
    • Result ranking by machine learning
  • References and further reading
  
  
• Flat clustering
  • Clustering in information retrieval
  • Problem statement
    • Cardinality - the number of clusters
  • Evaluation of clustering
  • K-means
    • Cluster cardinality in K-means
  • Model-based clustering
  • References and further reading
  • Exercises
  
  
• Hierarchical clustering
  • Hierarchical agglomerative clustering
  • Single-link and complete-link clustering
    • Time complexity of HAC
  • Group-average agglomerative clustering
  • Centroid clustering
  • Optimality of HAC
  • Divisive clustering
  • Cluster labeling
  • Implementation notes
  • References and further reading
  • Exercises
  
  
• Matrix decompositions and latent semantic indexing
  • Linear algebra review
    • Matrix decompositions
  • Term-document matrices and singular value decompositions
  • Low-rank approximations
  • Latent semantic indexing
  • References and further reading
  
  
• Web search basics
  • Background and history
  • Web characteristics
    • The web graph
    • Spam
  • Advertising as the economic model
  • The search user experience
    • User query needs
  • Index size and estimation
  • Near-duplicates and shingling
  • References and further reading
  
  
• Web crawling and indexes
  • Overview
    • Features a crawler must provide
    • Features a crawler should provide
  • Crawling
    • Crawler architecture
    • DNS resolution
    • The URL frontier
  • Distributing indexes
  • Connectivity servers
  • References and further reading
  
  
• Link analysis
  • The Web as a graph
    • Anchor text and the web graph
  • PageRank
    • Markov chains
    • The PageRank computation
    • Topic-specific PageRank
  • Hubs and Authorities
    • Choosing the subset of the Web
  • References and further reading
  
  
• Bibliography
• Index