Where does pattern collide?

A recognisable arrangement of features that the mind treats as a single whole and matches against representations already held in memory: the letters of a familiar word, a face, or a shape are perceived not as loose parts but as a configuration. Biederman's 1987 Recognition-by-components: A theory of human image understanding proposed that objects are recognised as arrangements of simple volumetric parts, so a stored structural description of the whole is compared with what the eye takes in. This page names the configuration itself, the thing that is recognised; the separate pattern recognition page treats the act of matching it. The referent is a perceived whole in a mind, not a reusable code solution, a spatial structure grown in tissue, or a repeated subgraph in a network.[1]

Unit

One perceived configuration treated as a single whole

Recovery means

Not applicable

Measured by

Studied by recognition accuracy and reaction time under varied views, degradation, and part deletion

A named, reusable scheme for solving a design problem that keeps recurring across programs: a pattern captures the roles, relationships, and trade-offs of a proven arrangement of objects, so a designer can apply it by name rather than reinventing it. Gamma, Helm, Johnson, and Vlissides's 1994 Design Patterns: Elements of Reusable Object-Oriented Software, the work of the group known as the Gang of Four, catalogued twenty-three such patterns and gave each a name, intent, and structure. The referent is a template for how to build software, described in prose and diagrams, not a perceived configuration in a mind, a spatial structure in an embryo, or a recurring motif in a graph.[2]

Unit

One named solution scheme, with an intent, structure, and trade-offs

Recovery means

Not applicable

Measured by

Judged by whether an implementation instantiates the pattern's roles and relationships, and by its effect on flexibility and coupling

The orderly spatial arrangement of cell types and structures that emerges as an organism develops, such as stripes, spots, or the ordered fields of a limb: the question is how an initially uniform group of cells becomes organised in space. Turing's 1952 The chemical basis of morphogenesis showed that reacting and diffusing chemicals can spontaneously break symmetry and settle into a repeating spatial pattern, and Wolpert's 1969 Positional information and the spatial pattern of cellular differentiation proposed that cells read their position from a gradient and differentiate accordingly. The referent is physical structure forming in living tissue, measured in cells and distances, not a perceived whole, a code template, or a graph motif.[3][4]

Unit

One spatial arrangement of cell types across a developing tissue

Recovery means

Not applicable

Measured by

Mapped by imaging gene expression and cell types in space, and modelled by reaction-diffusion or gradient equations

A small connected subgraph that appears in a network far more often than it would in a random network with the same basic statistics: such recurring wiring patterns are read as the building blocks of a network's structure. Milo, Shen-Orr, Itzkovitz, Kashtan, Chklovskii, and Alon's 2002 Network motifs: simple building blocks of complex networks introduced the term motif and a counting method, finding shared patterns across gene-regulation, neural, and engineering networks. The referent is a formal, over-represented subgraph counted against a null model, not a perceived configuration, a software template, or a structure grown in tissue.[5]

Unit

One subgraph type, counted by its frequency against a random baseline

Recovery means

Not applicable

Measured by

Enumerated by subgraph counting and compared with randomised networks to test over-representation