How to use the factor details tab for 2-level and quantitative designs


This help file describes how to input factor details for 2-level and quantitative designs

Inputs on tab Factor Details for all such menus

Common factor levels

can be checked to define a common set of factor levels that is used for all factors. The first level corresponds to -1 or the lower bound of the range of a quantitative factor, the second level to +1 or the upper bound of the range of a quantitative factor.

When unchecking the checkbox, levels can be individually adjusted for each factor. WARNING: Re-checking the box after individual level changes looses all settings.

Modify factor details for selected factor

is the frame in which changes can be made. A factor can be selected by clicking on the arrow below Select (and also by clicking on an item in the listboxes below the frame). Repeatedly jumping through the frame with the Tab key automatically cycles through the factors one by one.

The entry Comment or label is included into an exported html file as annotation for the factor. This may be useful for conducting the experiment.

Buttons for changing the factor order

If factor details have been entered and it is discovered later that the factors are needed in a different order (e.g. because of the alias structure of a regular 2-level fractional factorial design), the buttons Move Up and Move Down can be used for changing the order of the factors.

Hard to change factors

can be specified for regular 2-level fractional factorial designs, if special choices have been activated by the checkbox below the tab. This ascertains that the experiment can be run with as few as possible changes in the first (number to be specified) factors.

This should only be used if absolutely unavoidable, as it worsens the information on the affected factors.


Ulrike Groemping

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