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bob

Not sure that I agree with this blanket statement...

"This means that when creating a plot such as this, the designer must explain what MMI is in the footnote. Yes, on every chart even if every chart in the report deals with MMI."

Surely this would be unnecessary if every chart in the report deals with MMI. In fact, is this not adding additional junk to the page?

Floormaster Squeeze

I have no idea why you feel it necessary to chop off data at all. What is gained and what is lost? Well, I guess you gain the ability to see variance but as you lose the ability to quickly understand how much you lose the ability to understand the variance. Sure, you can look at the numbers more carefully and force yourself to think about it but then why do a chart at all.

The final chart is OK but I think column charts need to include the origin to be able to see the relative differences. In order to convince people of the importance of the origin I like to show people two charts (admittedly dual axis charts) that include the exact same data that appear to say completely different things simply because the scales have changed.

Your final chart works because the scale is already normalized but "chopping off" charts is exactly the kind of thing I would avoid in most situations (nearly all the charts I create are focused on relative comparison so the origin is important).

Kaiser

FMS: Thanks for the note, which tells me some readers may get confused by my presentation. I was walking through the steps that got the designer into this mess; I am definitely not advocating "chopping off" the base of bar charts. There are some old posts here in which I explicitly warn against such a practice.
Also, I want to draw attention to the difference between using 85 versus using 100 as the dividing line here, the benefit of which you nicely summarized.

Bob: I'm a stickler about such things. People who work for me can attest to that :) Ninety-percent of the time, we can get away with not explaining what is on the chart but the 10% of the time invariably will involve someone tearing out the one page and sending it to an important person. Within two seconds, said person will decide whether to move on, and we won't be around to explain what's on the chart. So yes, you should put the explanation on every page, even if it feels silly.

Floormaster Squeeze

I did not read carefully. My apologies.

LemmusLemmus

I clicked on the first thumbnail to enlarge the image of the graph before I read your text. It took me at least 15 seconds to figure out the chart has nothing at all to do with temperature. (Disclaimer: People tell me I'm literal-minded.)

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