Path: utzoo!utgpu!news-server.csri.toronto.edu!mailrus!cs.utexas.edu!uunet!decwrl!ucbvax!mtxinu!sybase!mercury!scottl From: scottl@mercury.sybase.com (Scott Luebking) Newsgroups: comp.cog-eng Subject: Re: Noun-Verb vs Verb-Noun Message-ID: <10316@sybase.sybase.com> Date: 29 Jul 90 17:17:12 GMT References: <1990Jul16.214644.3009@ee.rochester.edu> Sender: news@Sybase.COM Organization: Sybase, Inc. Lines: 99 Another way to look at the noun-verb order concerns the number of nouns which are involved. I think there are three cases which are: 1. one verb and no nouns 2. one verb and exactly 1 noun 3. one verb and 0 or more nouns The first one is the trivial case where the verb doesn't operate on any nouns. The second case is one where a noun must be provided for the verb. In this case, both pieces of information are needed before any error checking is done or any resources, e.g. locks, printers, are requested. Since both pieces are needed before any processing can continue, the order may not be as important. One consideration might be that if the verb is chosen first, the interface could indicate appropriate noun choices, e.g. highlighting or popping up menus or text fields. Similarly, choosing the noun first could allow the system to indicate appropriate verbs. The third case is used to specify several nouns. It is useful for specifying a list of objects where the action is performed on each object, e.g. printing a file. For an expert user, it increases effificiency because he/she specifies the verb only once instead of once for each noun. A list of nouns can alo be used to specify a relationship among the list of nouns or build a noun aggregate, e.g. specifying a group of the objects. Specifying a list of nouns can have one of the two following forms: ... ... In the first form, the verb has the dual purpose of specifying the action and terminating the list of nouns. In the other form, a terminator is used to signal the end of the list of nouns. The main advantage of the first form is that the user doesn't have to specify a terminator. The second form has several advantages. One advantage to the second form is that error and resource checking can be performed as each noun is selected rather than after the entire list is specified. Checking each noun as it is selected is much less frustrating for the user since the user knows immediately that there is a problem rather than at after specifying the entire list. If the error or resource checking occurs at the end of the list, the user will need to specify the entire list again. Also, if more than one noun has an error, pairing errors and nouns after the list is specified can be confusing or time consuming. Another advantage to the second form is that more support can be provided to the user when specifying complex syntax. Complex syntax has the advantage of improving user efficiency by increasing the brevity of commands. In this example: save noun-1 to noun-100 except noun-34 the "to" and "except" are nouns used to modify and shorten the command. The syntax uses fewer nouns than: save noun-1 noun-2 ... noun-33 noun-35 ... noun-100 Complex syntax also increases the expressability of the interface. In more complex syntax, the relations between the nouns and the order of the nouns becomes much more significant. The example could be written as: noun-1 to noun-100 except noun-34 save However, the interface cannot prompt as easily because it doesn't know the verb. Since the interface cannot assist the user through the complex syntax, the user will be forced to learn and remember the syntax. This user requirement will increase the amount of effort the user will need to exert in order to take advantage of the complex syntax. The result will be that few users will take advantage of the complex syntax which will thwart the purpose of the syntax. If the verb is at the beginning of the noun list, the interface can assist the user through complex syntax by prompting. The second form is much more user-friendly and can provide facilities which can significantly help expert users. If the application is simple with no noun aggregates and need not worry about expert users, the choice between noun-verb or verb-noun order can be made on other criteria. If the application is complicated or will have expert users, the verb-noun order is probably preferred because it can be expanded into supporting noun aggregates or more complicated syntax. -- Scott Luebking {mtxinu,sun,pyramid,pacbell}!sybase!scottl scottl@sybase.com