Word spaces, preceding or following punctuation, should be optically adjusted to appear to be of the same value as a standard word space. If a standard word space is inserted after a full point or a comma, then, optically, this produces a space of up to 50% wider than that of other word spaces within a line of type. This is because these punctuation marks carry space "above" them, which, when added to the adjacent standard word spaces, combines to create a visually larger space. Some argue that the "additional" space after a comma and full point serves as a "pause signal" for the reader. But this is unnecessary (and visually disruptive) since the pause signal is provided by the punctuation mark itself.