A parameter was a limit that defined how a task could be accomplished, such as a budget.
In 2364, after a series of formula modifications by Kosinski, the USS Enterprise-D experienced a phenomenal surge of power during a warp speed experiment and jumped over millions and later over a billion light years through space in a matter of minutes. During the first jump, instrumentation indicated that the ship actually surpassed warp 10, apparently making the so-called warp 10 barrier meaningless. Kosinski declared that science would need new definitions and new parameters to define warp speed. One suggestion was the Kosinski scale. It was later determined that the enormous surge of speed was caused by The Traveler and that Kosinski's formulas were bogus. (TNG: "Where No One Has Gone Before")