Classificacions

Classificacions is the plural form of classificació in Catalan, usually translated as classifications in English. It denotes both the act of organizing items into groups according to shared characteristics and the resulting groupings themselves.

In biology, classification, or taxonomy, places organisms within a hierarchical framework from kingdom to species. In library science, classification schemes such as the Dewey Decimal Classification and the Library of Congress Classification organize resources for retrieval. Information science distinguishes taxonomies, ontologies, and thesauri as systematic ways to describe concepts and their relationships.

Classifications can be hierarchical, where every item has a single parent category, or polyhierarchical, where items can belong to multiple, overlapping categories. They can be structured in flat lists or widespread with facets and multiple dimensions, allowing flexible categorization depending on purpose.

In data science, classification is a supervised learning task that assigns objects to predefined categories based on labeled training data. Common algorithms include logistic regression, decision trees, random forests, support vector machines, and neural networks, with evaluation using accuracy, precision, recall, and related metrics.

Classification systems evolve as knowledge grows; revisions in biology reflect new phylogenetic data, while digital classification increasingly relies on automated methods and ontologies to handle large, complex datasets. See also taxonomy, ontology, categorization.