The -exact- and -exactc- Commands
It is occasionally useful (in special cases) to use a command less powerful than -answer- to judge a response. Suppose you are teaching the precise format required on some business form, and you want the student to type “A B C” exactly, with three spaces between the letters. A match to “answer A B C” would occur no matter how the student separates the letters. One space, four spaces, a comma or a semicolon (any of these punctuations) are permissible separators as far as -answer- is concerned. Normally, this flexibility is beneficial to students because it keeps them from getting too hung up on petty details. If, however, it is the details that are important in a particular response, use an -exactcommand. In the present case, the statement “exact A B C” will be matched only if the student types exactly that string of characters: A, space, space, space, B, space, space, space, C.
The -answer- command does not permit punctuation marks in its tag, so that a response such as “a:b” must be judged with an -exact- command if the colon is important. While punctuation marks cannot appear in the tag of the -answer- command, the student can use them in a response. The -answer- command will treat all punctuation marks that the student uses as being equivalent to spaces. (As an alternative, the -change- command can be used to redefine the colon to be considered a “word” and not just as a punctuation mark, in which case the -answer- command can be used.)
It should be emphasized that it is easy to misuse the -exactcommand. The student should normally be given considerable latitude in the form of his or her response, such as is permitted by the -answer-, -concept-, and -ansv- commands. The -exact- command should be used sparingly, and only for short responses. It may be important for the student to know the exact format of something that is as long as:
3 No. 6 screws/516-213-86xq-4: New Orleans
In this case, it would certainly be preferable to have the student pick this correct form out of a displayed set of samples than to ask him or her to type it exactly. (Then, all the student would need to say is that item number 3 is the correct form.)
There is also a conditional form of the -exact- command, -exacts-. (The conditional -answer- command is called -answerc-.) In the case of the conditional form of the -do- command, the presence of commas tells TUTOR that the statement is conditional, so a -dos- command name is not needed. But -write-, -answer-, and -exact- may have tags which include commas, so the conditional command names must be different (-writec-, -answerc-, -exactc-).