Data Types

Data Types
When a file is created, you assign it a data type, based on whether it contains continuous measurement (variable) or discrete counts (attribute). This selection streamlines the analysis you can perform on the data. To change the data type, select the Change Data Type option from the Data menu, which opens the Set Data Type dialog box.

Note: You cannot change the Data Type if there are Chart Windows open which are based upon that data.
Variables: Data for each characteristic is entered into the characteristic’s respective column based on the column’s subgroup size. Since each column has a potentially different subgroup size, there will be some blank fields in the columns with smaller subgroup sizes, since each new subgroup starts on the same row. The Smart Cursor in Variables data sets option in the Preferences dialog box, available from the Options menu. will automatically move the cursor to the next applicable field.

Attributes: Each row contains a count of the characteristic (number of times characteristic was observed) with respect to a sample size. If the sample size varies, a column should be reserved for this entry. If it is constant, you can enter the sample size in the Analysis Options for the characteristic being analyzed.

Pareto: This data type, which is a carryover from older DOS packages from Quality America, is also supported. This file type is not generally recommended, since Pareto charts can be done from either Attributes or Variables data files, but attribute and variable charts cannot be done from Pareto files. Pareto files are formatted such that the rows represent characteristics, and the columns represent the time axis. Pareto files can be converted to either variables or attributes file type.

None: None is automatically set for a file imported from another application, unless you have set a default data set type in the Preferences dialog box.