With hundreds of pages covering formulas, definitions, and body-of-knowledge content across multiple certification bodies, mistakes happen. Here’s how I handle them.
How to Report an Error
If you spot something wrong, a formula that doesn’t match what you were taught, an outdated body-of-knowledge reference, a broken link, or a plain factual error, the fastest way to reach me is through the Contact page or a comment on the page in question. Comments are especially useful since other readers who hit the same question can see the fix too.
What Happens Next
I personally review every correction report. If it’s accurate, I fix the page directly rather than publish a separate retraction notice, this is a living study resource, not a news site, so the standard is “get the page right,” not “preserve a record of every past version.” For a factual error that affects an exam-relevant answer (a wrong formula, an incorrect key on a practice question), I prioritize the fix over routine content updates.
What Counts as a Correction vs. a Judgment Call
Some topics in Six Sigma have more than one accepted answer depending on which certification body or textbook you’re studying from (ASQ, IASSC, and Villanova don’t always agree on terminology or emphasis). When that’s the case, I try to note the difference on the page rather than pick a single “correct” answer and call competing views wrong. A true correction is a factual error; a difference in emphasis between certification bodies is something I’ll clarify, not necessarily change.
I’d rather hear about a mistake than have it sit uncorrected, so please don’t hesitate to flag one.