Selecting a Simple Non-Numeric Sample
Sometimes the values which we wish to select are not numeric. For example, the days of the work week: Mon, Tues, Wed, Thur, Fri. While these aren't numbers it would be a simple matter to associate the numbers 1 through 5 with the days and draw and sort them as numbers. We did something similar to this in the example above rather than put the names of the employees into the computer. However, with a list of thirty names or fewer, like the days of the week, the program lets us put in the names to make the sample results easier to read. Let us assume that we want to draw such a sample. We start as before by selecting d from the main menu, to describe our sample. We name the first category "Day". Then we are asked:
Is Day numbered or named?
We respond with named. (When the program askes for numbered or named you can simply type nu for numbered or na for named.) The program then lets us enter the names, asking:
Enter the names of Day in the order
that they are to be sorted. If you have entered all the names
just press Return
Enter the next name.
Here we enter Mon and press return. We do the same for Tue and for each day in order. When we complete the list of days we type nothing, but press the return. The machine asks for the next category and we press return again, because, as before, we have only one category. The design is displayed as:
Category 1 -- Day named Mon Tue Wed Thur Fri
Sometimes it takes a bit more understanding to recognize that we are dealing with names rather than numbers. Suppose we want to sample what employees are doing at various points in the workday. We need to select hours of the day from 9 am to 4 pm. Now we want the numbers 1,2,3,4, and 9,10,11,12 but not in that order and additionally we want a gap in the middle of our series of numbers. The program will handle such a situation, but it is necessary to recognize that we need to tell it to view the items sampled as names, not numbers, so we select the option named and enter 9 am, 10 am, and so on up to 4pm. Our design would look like this:
Category 1 -- Hour named 9am 10am 11am 12noon
1pm 2pm 3pm 4pm
And a sample from it would look like this:
We will use this sampling design later as part of a design to select times throughout the workday. This sample will be used by a manager to determine how her time is spent.
Some named categories, including the ones that we just created above, are so frequently used that, to save you time, the program has a special way of creating them.
this page is at http://testbed.cis.drexel.edu/sample/simspnon.html