The single designator "chair" is an ambiguous sign, Morris says. If we know only that a person ''holds a chair/1 it is impossible to know whether he is grasping something he can sit on or has an academic appointment. Morris says that a sign becomes unambiguous when it belofigs to a sign-family that has only one signification. This is saying, in more precise language, what has already been said. Only the context can provide the meaning.
The test of the adequacy of informative signs is in the response of the recipient. When the signs of the user become designators for the recipient, the signs are adequate.
Some designators denote. Others do not denote.
Those designators which denote are true. Those which do not denote are not true.
The reliability of the informative sign is proportionate to the frequency with which the designator denotes. Designators that denote consistently are the most reliable signs.
The unamblguity of a sign is established by Its membership in a sign-family which has a single signification.
B. The valuattve use and the appraisIve mode
When the waiter or the speaker uses signs with the primary purpose of provoking an attitude response in the recipient, he normally uses valuative language. As Morris puts it, the purpose of valuative language is to cause the recipient to accord "preferential status" to something.
How will the user of signs advance this purpose? He will select appraisors as the most appropriate mode of signifying. Appraisors of things, of people, of situations, of plans, etc., place a value on the thing signified. The appraisor may be negative or positive; high or low; for or against.32
32 Work is now being done to "measure" appraisers. See Osgood, Suci, and Tannenbaum, The Measurement of Meaning.