Six Sigma Black Belt Certified Practice Exam

Which of the following best describes a controlled variable whose influence on a response is being studied?

1. Replicate

2. Version

3. Level

4. Factor

The correct answer is: Factor

A controlled variable whose influence on a response is being studied is best described as a factor. In the context of experimental design and analysis, factors are the independent variables that researchers manipulate to determine their effect on the dependent variable, or response. In Six Sigma methodologies, particularly in designed experiments (DOE), factors can vary at different levels to assess how they impact the overall process or outcome. Understanding how these factors influence the response helps in identifying the optimal conditions for process performance, thereby leading to improved quality and efficiency. The other terms mentioned—replicate, version, and level—serve different purposes in experimental design. Replication refers to the practice of repeating experiments to ensure reliability and accuracy, while version may relate to differing iterations or iterations of a process or product that don't directly control the variables in the same way. Level specifically refers to the specific values or settings that factors can take during an experiment, which is an aspect of factors but not their defining concept. Thus, factor is the term that encapsulates the relationship between controlled variables and their studied influences on the response in a way that is central to Six Sigma practices.