Guided Practice 1.1 - Solution

The question was:

Classify each of the following kinds of information as one of:

• Scalar
• Itemization
• Compound
• Mixed

Solutions:

1. A weight: Weight is a number, therefore it is scalar information
2. A guitar in a guitar shop's inventory: The information for a guitar might consist of type, make, model, year, serial number, and probably other information as well; therefore it is compound information.
   (Alternatively, we might say there are various kinds of guitars, such as electric and acoustic, with each kind described by compound information; guitars would then be an example of mixed information.)
3. A day of the week: There are exactly seven days in a week, so there are exactly seven possible values. Therefore it is itemization information.
4. An order in a restaurant: In a restaurant, there are several dishes on the menu. For each kind of dish (steak, salad, sandwich) we probably need to include several items of information, such as quantity, price, plus special information for each dish (e.g. rare, medium, or well-done for a steak, "dressing on the side" for a salad, or kind of bread for a sandwich). So we have several variants of information (one per menu item), each of which is compound information. Therefore it is classified as mixed information.
5. An automobile in a dealer's showroom: The information for an automobile might consist of make, model, year, serial number, and probably other information as well; therefore it is compound information.
6. A College Degree: The answer depends on the application. Perhaps we just need to keep track of the level of the degree: bachelor's, master's or Ph.D. That would be itemization information. Or we might need to keep track of both the level and major. That would be compound information. Or we might want to allow 'None' as a possibility and still keep track of the level and major. That would be mixed information. Or perhaps we're talking about a particular student's degree, in which case we might want to keep track of the date as well.

Note that the same kinds of arguments we made about the College Degree could be made almost as easily for some of the other examples as well. Data Design could be (and often is) a whole course by itself.