Subtypen

Subtypen, or subtypes in English, refer to a more specific form within a broader category. They preserve the essential identity of the parent type while exhibiting distinguishing traits that justify a separate label. Subtypes organize variation for analysis and communication across disciplines. Boundaries between subtypes are often pragmatic and not universally fixed; some contexts rely on expert consensus, others on measurable criteria.

In biology and medicine, a disease subtype denotes a distinct form of a disease with characteristic features such as etiology, pathology, or treatment response. Subtypes may reflect genetic differences, biomarker status, or clinical presentation. The term is sometimes used informally alongside subspecies, but subspecies is a formal taxonomic rank. Examples include influenza A subtypes such as H1N1 and H3N2, and breast cancer subtypes defined by receptor status (ER, PR, HER2).

In computer science, subtyping is the relationship by which a type is a subtype of another type; a value of the subtype can be used wherever a value of the supertype is expected, enabling polymorphism. Some languages distinguish nominal subtyping (based on declared relationships) from structural subtyping (based on actual structure). Subtypes can be implemented via class hierarchies, interfaces, or advanced type systems.

In other fields such as linguistics, psychology, and information science, subtypes capture meaningful variation within a category, supporting precise description and categorization without proliferating new types.

Challenges include over-fragmentation, ambiguous criteria, and subtype creep. Clear definitions and validation against data are important to maintain usefulness of subtypes. Notable examples include cancer subtypes and language variety subtypes used in research and clinical practice.