Corner case
Encyclopedia
A corner case is a problem or situation that occurs only outside of normal operating parameter
s – specifically one that manifests itself when multiple environmental variables or conditions are simultaneously at extreme levels, even though each parameter is within the specified range for that parameter.
For example, a loudspeaker might distort audio, but only when played at maximum volume, maximum bass, and in a high-humidity environment. Or a computer server may be unreliable, but only with the maximum complement of 64 processors, 512 GB of memory, and 10,000 signed-on users.
Contrast a corner case with an edge case
, an issue that occurs only at a (single) maximum or minimum parameter. For example, a speaker that distorts audio at maximum volume, even in the absence of other extreme settings or conditions.
Corner cases are part of an engineer
's lexicon – especially an engineer involved in testing or debugging
a complex system. Corner cases are often harder and more expensive to reproduce, test, and optimize because they require maximal configurations in multiple dimensions. They are frequently less-tested, given the belief that few product users will, in practice, exercise the product at multiple simultaneous maximum settings. Expert users of systems therefore routinely find corner case anomalies, and in many of these, errors.
The term "corner case" comes about by physical analogy with "edge case". Where an edge case involves pushing one variable to a minimum or maximum, putting us at the "edge" of the configuration space
, a corner case involves doing so with multiple variables, which would put us at a "corner" of a multidimensional configuration space.
Parameter
Parameter from Ancient Greek παρά also “para” meaning “beside, subsidiary” and μέτρον also “metron” meaning “measure”, can be interpreted in mathematics, logic, linguistics, environmental science and other disciplines....
s – specifically one that manifests itself when multiple environmental variables or conditions are simultaneously at extreme levels, even though each parameter is within the specified range for that parameter.
For example, a loudspeaker might distort audio, but only when played at maximum volume, maximum bass, and in a high-humidity environment. Or a computer server may be unreliable, but only with the maximum complement of 64 processors, 512 GB of memory, and 10,000 signed-on users.
Contrast a corner case with an edge case
Edge case
An edge case is a problem or situation that occurs only at an extreme operating parameter.For example, a stereo speaker might distort audio when played at its maximum rated volume, even in the absence of other extreme settings or conditions.An edge case can be expected or unexpected...
, an issue that occurs only at a (single) maximum or minimum parameter. For example, a speaker that distorts audio at maximum volume, even in the absence of other extreme settings or conditions.
Corner cases are part of an engineer
Engineer
An engineer is a professional practitioner of engineering, concerned with applying scientific knowledge, mathematics and ingenuity to develop solutions for technical problems. Engineers design materials, structures, machines and systems while considering the limitations imposed by practicality,...
's lexicon – especially an engineer involved in testing or debugging
Debugging
Debugging is a methodical process of finding and reducing the number of bugs, or defects, in a computer program or a piece of electronic hardware, thus making it behave as expected. Debugging tends to be harder when various subsystems are tightly coupled, as changes in one may cause bugs to emerge...
a complex system. Corner cases are often harder and more expensive to reproduce, test, and optimize because they require maximal configurations in multiple dimensions. They are frequently less-tested, given the belief that few product users will, in practice, exercise the product at multiple simultaneous maximum settings. Expert users of systems therefore routinely find corner case anomalies, and in many of these, errors.
The term "corner case" comes about by physical analogy with "edge case". Where an edge case involves pushing one variable to a minimum or maximum, putting us at the "edge" of the configuration space
Configuration space
- Configuration space in physics :In classical mechanics, the configuration space is the space of possible positions that a physical system may attain, possibly subject to external constraints...
, a corner case involves doing so with multiple variables, which would put us at a "corner" of a multidimensional configuration space.
See also
- Boundary caseBoundary caseThe term boundary case is frequently used in software engineering to refer to the behavior of a system when one of its inputs is at or just beyond its maximum or minimum limits...
- Black swan theoryBlack swan theoryThe black swan theory or theory of black swan events is a metaphor that encapsulates the concept that The event is a surprise and has a major impact...