Advanced statistical analysis tools including hypothesis testing and control charts tested on Six Sigma Black Belt exams, beyond the Green Belt DMAIC basics.
40 cards · basic cards · AI-written, checked twice. Edit anything.
- What is the difference between a Type I error and a Type II error?
- Type I is rejecting a true null hypothesis (false positive); Type II is failing to reject a false null hypothesis (false negative).
- What is the primary purpose of a control chart in Six Sigma?
- To monitor a process over time and detect whether it is in statistical control or has gone out of control.
- What is statistical power in hypothesis testing?
- The probability of correctly rejecting a false null hypothesis; the ability to detect a true effect, equal to 1 minus beta.
- What is a p-value?
- The probability of observing data as extreme as or more extreme than what was observed, assuming the null hypothesis is true.
- What does the alpha level (significance level) represent?
- The probability of making a Type I error; the threshold below which a p-value is considered statistically significant.
- What is the difference between a one-tailed and a two-tailed hypothesis test?
- One-tailed tests for effect in one specific direction only; two-tailed tests for difference in either direction.
- What does a Normal Probability Plot assess?
- Whether data follows a normal (Gaussian) distribution; points close to a straight line indicate normality.
- What does a Gage R&R study measure?
- The amount of variation in a measurement system due to the equipment (repeatability) and different operators or conditions (reproducibility).
- What does the capability index Cpk measure?
- How well a process can produce output within specification limits, accounting for centering; compares process variation to tolerance.
- What is the difference between Cp and Cpk?
- Cp assumes the process is centered between specifications; Cpk accounts for actual process centering and is always less than or equal to Cp.
- When should you use a non-parametric test instead of a parametric test?
- When data is not normally distributed, when sample size is very small, or when working with ranked or ordinal data.
- What is stratification in data analysis?
- Dividing data into subgroups or strata based on a factor to reveal patterns that might be hidden in the overall data.
- What is an interaction effect in an experiment?
- When the effect of one factor on the response depends on the level of another factor.
- What is blocking in experimental design?
- Grouping experimental units into homogeneous blocks to reduce the effects of nuisance variables.
- What does a main effects plot show?
- How the average response changes across different levels of each factor, graphically comparing factor impacts.