if I had just one shot to share an important ideahttps://abs.twimg.com/emoji/v2/... draggable="false" alt="💡" title="Elektrische Glühbirne" aria-label="Emoji: Elektrische Glühbirne">here it is. No joke. Look https://abs.twimg.com/emoji/v2/... draggable="false" alt="👀" title="Augen" aria-label="Emoji: Augen">

RATIOS DEMAND LOG SCALE

https://abs.twimg.com/emoji/v2/... draggable="false" alt="👇" title="Rückhand Zeigefinger nach unten" aria-label="Emoji: Rückhand Zeigefinger nach unten"> the coolest non-trivial example when a log Y-axis is required to represent ratios

going from 50 in ~1988 to 25 in ~2001 is as bad as going from 100 in 1970 to 50 in ~1988

Fascinating how the data story is changing – the seeming recent plateau is no longer there. And log *is* the *right* way to represent the nature of the data and tell the story.

The plots above are made by @CedScherer using @WWF data via @OurWorldInData https://ourworldindata.org/grapher/global-living-planet-index?country=~Freshwater">https://ourworldindata.org/grapher/g...

Here are the two tweets by @CedScherer prepared for today& #39;s #30DayChartChallenge https://twitter.com/CedScherer/status/1380223704811106308">https://twitter.com/CedSchere...

RATIOS appear whenever you divide something by something else of a similar class/nature. Ratios are dimensionless. The most common "hidden" case is time series standardisation when some year is taken for 100%, like 1970 in the example above

The thing is: the story (the shape of the line) will change depending on the arbitrary choice of the year taken as 100%. We divide all other years by this standard effectively creating *ratios*

I genuinely believe this is *the* most common #dataviz issue

It also often becomes a problem in statistical analysis – log transformation of the ratios are required before regression/correlation analysis is performed on the data

[side note]
It& #39;s even more important than the ones coming right after:
– #RotateTheDamnPlot
– #IncreaseTheDamnFont

The realisation of this simple data visualization and analysis rule literally took me ages of slow mind walk: from odds ratios through other explicit ratios to the "hidden" ones like here. Even color bars in the plot legends should be log transformed if they colorcode ratios!

I lost track how many times I& #39;ve pointed this out https://abs.twimg.com/emoji/v2/... draggable="false" alt="😅" title="Lächelndes Gesicht mit offenem Mund und Angstschweiß" aria-label="Emoji: Lächelndes Gesicht mit offenem Mund und Angstschweiß">

RATIOS DEMAND LOG SCALE

The idea to write a blog post on visualizing ratios correctly lives in my head and to-do list for well over a year now

Let me use this thread to legally bind myself to write it up soon https://abs.twimg.com/emoji/v2/... draggable="false" alt="🔗" title="Link Symbol" aria-label="Emoji: Link Symbol">