On some occasions (e.g., the Emergency Room Example recoding example), you will have factor and response data saved in a Minitab worksheet that was not created using Minitab's Stat>DOE>Factorial>Create Factorial Design window. Before you can analyze this data in Minitab, it has to be saved as a design object. To do this, select Stat>DOE>Factorial>Define Custom Factorial Design. Enter your factors in the Factors window (the response is not part of the design, and does not need to be specified). Select the Low/High button and either enter your factor names and levels or confirm the default factor names and levels. Click OK to leave the Low/High window, then click OK again. You will notice that Minitab has added several columns to the worksheet (there are also some internal variables created that are not visible). You are now free to analyze this as a conventional DOE.