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Information retrieval

As explained in Ensemble Methods for Machine Learning

Information retrieval is the field concerned with finding and ranking relevant information items in response to queries.

Information retrieval finds documents that match a user’s query and ranks them by relevance. Web search, legal research, literature surveys, and related-article features all use this basic pattern. section 5.0 section 5.5

A retrieval system addresses two linked problems:

  • Find documents matching the query. section 5.5
  • Rank the matching documents according to their relevance to the user. section 5.5
  • Represent each query-document pair with a relevance class such as least relevant, moderately relevant, or highly relevant. section 5.5

Legal-archive search

A paralegal searches previous cases to establish precedent and research case law; the system returns documents ordered by their relevance to the query. section 5.5

The retrieval task can be modeled with gradient-boosting classifiers. LightGBM supports the relevance-class case study, while XGBoost enables a later comparison and randomized cross-validation for parameter selection. section 5.5 section 6.5

How Ensemble Methods for Machine Learning covers it

How deep it goes
Explains retrieval through matching, ranking, and three-class relevance modeling, then stops at model comparisons.
Examples
Uses web search, legal archives, journal databases, related articles, and query-document relevance classes as examples.
What it assumes
Assumes familiarity with queries, documents, and relevance while connecting retrieval modeling to gradient descent and boosting.
What you can do after
Apply information retrieval via LightGBM or XGBoost to classify query-document relevance and compare model performance.
How it connects
Connects information retrieval with gradient boosting, classification, LightGBM, XGBoost, and randomized cross-validation.

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Related concepts

This explainer was generated by Manning's knowledge graph from the text of Ensemble Methods for Machine Learning. The section links point to the parts of the book it draws on.