WINKS Manua -- Chapter 1, Part4

WINKS Online Manual

Chapter 1 Part 4

EXAMPLE 3 - Creating a Database

This example shows you how to create a database, then use the information in the database to perform an analysis and display a graph.

Suppose you are testing the effectiveness of four kinds of hog feed. You randomly assign 15 hogs to 4 groups and feed each group one of the feeds. You want to use a one-way analysis of variance (independent group) to analyze this data. This example shows how you would create an appropriate database, enter the data, and perform the analysis.

Step 1: From the File menu, choose "New Database." You are asked to enter the name for your new database. Enter HOG (Or any DOS compatible filename.) Choose OK. (Note:This database is the same as the HOGDATA.DBF file on your disk.)

Step 2: - A dialog box will appear listing database types. Click on the down arrow at the right of the text field to display the options. See Figure 8.



	Figure 1.8. Selecting a pre-defined database type.

To create a database for this analysis, choose the option "Independent Group t-test or ANOVA" from the list and choose OK.

Step 3: An empty spreadsheet will appear containing the two fields: GROUP and OBS. The GROUP field will contain a code for feed type. For this example we'll use 1,2,3, and 4. The OBS field will contain the variable you observed. In this case it is weight gain. Enter the following data into the spreadsheet. Enter one row at a time. When you enter a complete row, and press Enter on the OBS field cell, a new row will be added to the spreadsheet.

Note:

You should not press enter on the last row, so you won't end up with a row of blank cells. If you do end up with a blank row, click on it, then choose "Delete Row" from the Edit menu to delete that row before saving the database

The HOG database values are:

GROUP      OBS(WEIGHT)
1                     60.8
1                     67.0
1                     54.6
1                     61.7
2                     78.7
2                     77.7
2                     76.3
2                     79.8
3                     92.6
3                     84.1
3                     90.5
4                     86.9
4                     82.2
4                     83.7
4                     90.3

Your spreadsheet, once you have entered the data, should look like Figure 9.



	Figure 1.9. Data spreadsheet showing HOG data.

Step 4: When you have finished entering the data, select the "Exit Edit" option from the File menu. You will be asked if you want to save the data before exiting. Answer "Yes."

Step 5: Click on the Analyze menu and select the "test and ANOVA" option. A sub menu will appear. From the sub-menu, choose the "Independent Group (t-test/ANOVA) option.

Step 6: Choose what fields to use. A dialog box appears allowing you to select which fields to use for this analysis. Select the GROUP field, and click on the GROUP button. Then select the OBS field and click on the ADD button. Your field choices will look like the dialog box in figure 1.10. Click OK to continue.



	Figure 1.10. Selecting Fields for ANOVA Analysis.

Step 7: After a few moments of calculation, the View Results Window will appear containing the output information for this analysis, as shown in figure 1.11. See Example 1 for more information on the View Results Window. Use the scroll bars to view output analysis text that is off-screen. Print the output by clicking on the "Print" button.



	Figure 1.11. Results of ANOVA Analysis.

Note:

If you only want to print or save a portion of the output, first highlight the text by clicking and holding the mouse button, and dragging the mouse to highlight the area, then choose "Print" or "Save."

Step 8: Click on the "Graph" button on the View Results Window to view the graph associated with this analysis. The default graph, shows a box and whiskers plot comparison, is shown in figure 1.12.



	Figure 1.12. Box and whiskers plot for Hog data.

Step 9: From the group comparison plot, you can select from among a variety of display options. Click on the "Options" button to display the options menu for the graph.

Step 10: For this example, check the following options (and uncheck all other options) on Graph Options dialog box:

§ Display Means

§ Error Bar (+/- St. Error of the Mean)

§ Connect Means

§ Bar Graph of Means

The graph, as shown in Figure 13, will be displayed. Print the graph by clicking on the "Print" button.



	Figure 1.12. Box and whiskers plot for Hog data.

Step 11: This ends the examples. Exit WINKS by clicking on the Exit Arrow on the WINKS icon bar or by choosing Exit from the File menu.

Continue to Chapter 2. (Using the WINKS Database.)