How to Design a 2K Experiment
How to Systematically Design the 2K Factorial Experiments Using MS Excel.
The step by step development and design process of the 2K factorial design of experiment is described using MS Excel with examples in Video 4. Originally, the method of development of the 2K design was described in many classic (Kempthorne 1952; Yates 1978) and recent texts (Box, Hunter et al. 2005; Montgomery 2019). However, in manual calculations for understanding the detail design and analysis process, utilizing MS excel reduces the work about 99.99% [a bit exaggerated].
The development starts with the basic 22 design. The step by step development process of the 2K is provided below. However, watching the video will be easier to follow than this text, probably.
1. Create the basic 22 design as in Table 4.
Table 4. The basic 22 design, including the standard order (SO) and the treatment combinations (TRT).
2. To add the third variable (factor), C to this 22 basic design, all treatment combinations of the basic design are added with both the low and the high level of the third variable, C. Add a column after the variable B and name it as “C.”
3. Fill the empty cells with all low level of C.
4. Add another four rows
5. Copy the basic design in the empty cells below the A & B columns.
6. Now add the high level to the empty cells below the C column.
7. Fill the empty cells of the TRT column with the appropriate treatment combinations
8. Similarly, fourth, fifth and more variables can be added to the design as needed. MS Excel File 1 provides an example containing 2K design up to eight variables, 28 is provided here.
MS Excel File 1. 2K design development process in MS Excel