Which of the following actions is part of pre-experimental planning?

The correct answer is B. Selecting the intended response variable . In the CSSBB DOE planning material, one of the earliest planning steps is to set objectives and select process variables , including both inputs and outputs. The source specifically defines the response variable as the variable that shows the observed result of an experimental treatment and notes that good DOE practice includes selecting all relevant responses during planning.

This is clearly part of pre-experimental planning , because before running any trials, the team must decide what outcome will be measured and optimized. Without a clear response variable, the experiment cannot be structured properly, analyzed correctly, or linked to project objectives. Determining critical values is usually associated with later statistical decision-making, not the basic front-end design of the experiment. Increasing the number of experiments while reducing sample size is not a standard first-step planning rule, and ensuring that only one person conducts each experiment is not a general DOE principle. CSSBB guidance instead emphasizes defining objectives, understanding the process, choosing factors and responses, confirming the measurement system, and then selecting the design. Therefore, selecting the intended response variable is the best answer.