klassering

Klassering, or classification, is the systematic process of organizing objects, data, or concepts into groups called classes based on shared characteristics. The aim is to simplify complexity, enable efficient retrieval, comparison, and analysis, and support decision making. The term can also imply a grading or rating assigned to an item, indicating its quality, severity, or level within a predefined scale.

Classification schemes can be hierarchical, with levels from broad to specific (taxonomy), or non-hierarchical, as in tag-based systems. They can be exclusive, assigning each item to a single class, or multi-label, allowing multiple classes per item. The work often involves defining the scope, selecting criteria, and maintaining the taxonomy as new knowledge or items emerge. Controlled vocabularies, taxonomies, ontologies, and metadata schemas are common tools.

In libraries and information management, classification systems group materials by subject or format (for example, Dewey Decimal or Library of Congress). In commerce and digital platforms, products, content, and users are categorized to improve search and personalization. In waste management, materials are sorted into recyclables, organics, and residuals. In science, biology uses taxonomic classification; in medicine, diagnostic codes classify diseases and procedures.

In machine learning, klassering refers to automated assignment of instances to predefined classes using algorithms; common approaches include supervised learning, with evaluation via accuracy, precision, and recall. The field faces challenges such as standardization, subjectivity, and keeping classifications up to date.