mindmap root((标准)) standard applies to any authoritative rule, principle, or measure by which the qualities, worth, or nature of something can be measured: the book is a classic by any ~. criterion may apply to anything used as a test of quality whether formulated as a rule or principle or not: in art there are no hard-and-fast ~ria. gauge applies to a means of testing a particular dimension such as thickness, depth, or diameter, or a particular quality or aspect: congressional mail is not always an accurate ~ of public opinion. yardstick is an informal substitue for standard or criterion that suggests quantity more than quality: the movie was a flop by most ~. touchstone suggests a simple test of the authenticity or value of something intangible: fine service is one ~ of a first-class restaurant.