(programming, object-oriented programming) principle that states that once an interface has become too large, it needs to be split into smaller and more specific interfaces so that any client of the interface will only know about the methods that pertain to itself. (In other words: no client should be forced to depend on methods it does not use.)

(object-oriented programming) A principle stating that any type having a subtype should be replaceable by its subtype without altering any of the desirable properties (such as correctness, task performed, etc.) of the program.

(software, design) a technique by which classes may achieve polymorphic behavior and code reuse by containing other classes that implement the desired functionality instead using inheritance.

Alternative form of Le Chatelier's principle

(software, user interface, design) A principle that the design should match the user's experience, expectations, and mental models.

(software, object-oriented programming) Synonym of Law of Demeter

(physics) also known as the stationary action principle. In complex systems, the tendency for any movement or change to use the least action, and therefore amount of energy possible. This is true on a subatomic level, on the population level (evolution), and on a macro level. Not considered a law of physics because it is not true 100% of the time.

(mathematics) A principle that gives a condition for finding the eigenvalues for a real symmetric matrix.

A method of analysis applied to problems of wave propagation, stating that every point on a wavefront is itself the source of spherical wavelets, and the secondary wavelets emanating from different points mutually interfere.

The principle that the parties in a transaction should be independent and on an equal footing, without any favorable treatment, fiduciary duties, etc.