VARIABLE SELECTION
CLUSTERING
VISUALIZING
MANAGING DATA
PRINCIPAL COMPONENTS ANALYSIS
MINIMUM DESCRIPTION LENGTH

Variable Selection

One of the key decisions a user must make before executing the data analysis tools is to select the variables to use. It is not necessary to use all of the variables in a data set, and often this is not desirable.

To select and weight the variables use the select variables button on the left of the WLV screen. You do not have to be in the Data tab to select variables. Clicking on the select variables button brings up a list of all of the variables in the data set, as shown below.

Next to each variable is a checkbox and a text box. The checkbox selects whether a variable is to be used (active). The text box indicates the relative weight of the variable. If all of the weights are the same, then each variable is treated equivalently during the data analysis. Variables with higher weights will receive proportionately more importance in subsequent analyses. Weights can be any non-negative number, including decimals. It is good to try the first analysis of a data set with uniformly weighted variables (the default values).

Once you have chosen the active variables and specified their weights, you must click the button that says set these variables as active at the bottom of the variable list in order to save your settings. After you have saved the active variables, WLV will print out the current set of active variables and their weights on the screen.



VARIABLE SELECTION
CLUSTERING
VISUALIZING
MANAGING DATA
PRINCIPAL COMPONENTS ANALYSIS
MINIMUM DESCRIPTION LENGTH