Basic Question - Central Composite Design
Hello, I wondered if I could ask a question about orthogonality of the squared term columns in a Central Composite Design (CCD) with two factors A and B. The dot product of any pair of columns in the model matrix is always zero - I always understood this to mean that the column (vectors) of say A with B or B with AB or B with B^2 are orthogonal (at right angles to) each other so their beta's can b...