I want more people to read this article. It's the basics everyone should know. Day to day I see charts that are just not right and it bothers me. My main concern is disillusion when you read some charts. I can see many other things that could potentially included in this article, but then it'd be way too long for an article.

But then again it comes down to how the person designing can think. Best practice is to ask someone (who has no idea about the data) and ask him to explain what the data represents. If it's not instant correct response (if the given aggregated data are not THAT complicated), there's surely space for improvement. User testing is critical in defining how an information is perceived.