polarity

n 1: a relation between two opposite attributes or tendencies;

"he viewed it as a balanced polarity between good and

evil" [syn: {mutual opposition}]

2: having an indicated pole (as the distinction between

positive and negative electric charges); "he got the

polarity of the battery reversed"; "charges of opposite

sign" [syn: {sign}]

parity

An extra bit added to a {byte} or

{word} to reveal errors in storage (in {RAM} or {disk}) or

transmission. Even (odd) parity means that the parity bit is

set so that there are an even (odd) number of one bits in the

word, including the parity bit. A single parity bit can only

reveal single bit errors since if an even number of bits are

wrong then the parity bit will not change. Moreover, it is

not possible to tell which bit is wrong, as it is with more

sophisticated {error detection and correction} systems.

See also {longditudinal parity}, {checksum}, {cyclic

redundancy check}.

(1996-03-01)