2k Factorial Design. The first X1 column starts with -1 and alternates in sign for all 2 k runs. Factors can be quantitative or qualitative.
For example with two factors each taking two levels a factorial experiment would have four treatment combinations in total and is usually called a 22 factorial design. The first X1 column starts with -1 and alternates in sign for all 2 k runs. For the vast majority of factorial experiments each factor has only two levels.
The 2k Factorial Design Montgomery chap 6.
Can compute main effects and all multi-factors interactions. A half-fraction fractional factorial design would require only half of those runs. A key use of such designs to identify which of many variables is most important and should be considered for further analysis in more detail. We will discuss designs where there are just two levels for each factor.
