Recent comments in /f/dataisbeautiful

shmerham t1_izg5udz wrote

I’m not sure I’d agree that 1 is not ok in most instances. It’s okay if you’re comparing values against a reference, particularly if you’re trying to show outliers.

Take, for example, 100 meter dash times. There’s a huge difference between 10.0 and 9.9 seconds (a body length). …and if you’re trying to compare Usain Bolt’s record against the other fastest times, you would need to truncate the axis to see that his fastest stands out against the next 9 fastest runners which are clustered together.

There just one example but there’s plenty of others.

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notkevinjohn t1_izg4zbw wrote

Because that analogy just doesn't map to the situation here. There aren't certain plotting/graphing practices that are more likely to be associated with misleading data then they are with accurate data (except maybe not putting labels on your axis). You are making the assumption that if you see plots that do this, they are more likely to be misleading than accurate, but I don't think the data support that claim. I do everything on this list all the time in my job as an engineer, and I am doing it because it's the most accurate way to answer the questions that my data were collected to answer.

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AtLukesDiner t1_izg4qby wrote

I mean there's nothing to the left of the bars specifying the unit and scale... Is it percentage points? 0-100 or 0-10? We have no clue. It ties into the first point noting how important the scale is to putting the data in context.

EDIT: I also have no idea how I made the text large but I have been watching a 6 day old baby since 4am and cannot be held responsible 😂

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JoHeWe t1_izg4qb3 wrote

There are instances where starting the Y-axis not at zero is okay. I'm bad at examples, but zero is used as a baseline. Which means that it would be better to start the Y-axis at another value, it being similar to the baseline.

An example might be the concentration of something, like CO2 molecules in the atmosphere. It is impossible and irrelevant to get to 0. Besides, it's not about the absolute values but the relative values.

But in general, yeah, it is misleading.

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dark_o3 OP t1_izg2w9t wrote

If I travel to another country, I would like to know about common tourist scams, so if for example someone wants to sell me a bracelet on the street, I will be extra careful with the purchase. I’ll approach carefully, ask questions, evaluate situation, etc. Why cant we apply same principle here?

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bosschucker t1_izg17rg wrote

I have to disagree with #2. I'm a fan of this blog post by datawrapper, which features this graphic (and has more arguments against dual axis charts besides being misleading). you can manipulate the axes to show literally any correlation that you want, which is a pretty fatal flaw imo for any data visualization

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