Kinds of Statistics
Kinds of Statistics. Photo by Andrew Tarvin

Not all statistics are the same. It’s useful to discern between the various types of statistics when doing analysis. Remember;

  • a statistic is a value obtained from the sample or a calculation.
  • a parameter is a value found or estimated from the population.

Analytical statistics aka Inferential Statistics

What are Inferential Statistics?

When do you use Inferential Statistics??

Examples of Inferential Statistics in a DMAIC Project

Descriptive statistics (aka Enumerative statistics)

What are Descriptive Statistics?

  • Typically used for the whole entire population, not just a sample.
  • Using a graph or population parameter
  • Organize or summarize information
    • Mean, median, mode
    • Graphs, charts & plots
    •  

When do you use Descriptive Statistics??

Examples of Descriptive Statistics in a DMAIC Project

(Walkthrough each one listed with an example)

Assumptive statistics

  • No such thing.

Helpful Articles

http://www.micquality.com/six_sigma_glossary/analytical_descriptive_statistics.htm (Descriptive vs. inferential statistics)

ASQ Six Sigma Green Belt Kinds of Statistics Questions

Question: The statistics that summarize a population are referred to as

(A) categorical statistics
(B) descriptive statistics
(C) probabilistic statistics
(D) control statistics

Answer: (B) Descriptive statistics summarize a population. The other options are nonsensical.

Comments (2)

3. The percentages of total quality cost are distributed as follows: prevention 12%, appraisal 28%, internal failure 40%, and external failure 20%. One would conclude:

a. More money should be invested in prevention
b. Expenditures for failures are excessive
c. The amount spent for appraisal seems about right
d. Nothing

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