6 ms·

Some of the comments at the bottom of the article lament the "innumerancy" of the general public. But let's be honest: logarithmic scales take effort to read.

Some of the comments at the bottom of the article lament the "innumerancy" of the general public. But let's be honest: logarithmic scales take effort to read. And like any kind of communication, you should make it easy to read. As a person who creates and looks at charts all day, I can read complex charts. But I really prefer other people use linear charts of simple bars or trend lines. You're conveying a new idea to me, so don't assume I have all the context you do when reading the chart. If you want to show acceleration, remember to use different units. Choose a unit that can be shown on a linear scale. E.g., the ratio of today's cases over the cases from a week ago.

mytailorisrich 6y ago
Well log scale is intended to make it easier to read... In general it is used in cases where a linear scale would be unreadable. Your suggestion about changing what is represented in order to avoid a log scale is good but does not solve the root of the issue: many members of the public will not understand the information however it is represented because the concept itself is too complex. It really is a numeracy problem.
- redis_mlc 6y ago
  Blaming the people you're trying to communicate with is not a winning move. When you look at the 2 graphs side-by-side, as in the article, it's apparent which conveys more meaning (the linear one), unless I suppose you read log graphs all day. The public does not.
  - mytailorisrich 6y ago
    Blaming would be to claim that it is their fault for not understanding. Here it is not blame, it is a statement that anything above the most basic maths concepts will stump a surprisingly large number of people. I'm not sure 'surprisingly' is the right word but here it is.
- vharuck 6y ago
  I've found that, if somebody has trouble understanding a type of statistic (log-scaled, survival rate, confidence interval), it's because they never use them. You could say we should teach these things in high school, but why? So we can effectively communicate data they still won't use? Throwing more math, tech notes, or gentle introductions at the communication problem has never worked for me. What has worked is expressing the concept in the most "real" terms possible. Epidemiologists are worried about exponential growth because it means hospitals will be swamped. That worry should be the topic when communicating with the public. How long until that's projected to happen? Maybe show the linear trend with a horizontal line for capacity and dotted line for a forecast of need. Put a huge red circle around where they intersect. Even better: just write "X days predicted until overrun." Also, charts are terrible for reading data. They're good for comparisons, trends, and distributions. I only use them for exploring or summarizing. Tables are for readable numbers.
_bxg1 6y ago
They take effort to read even when you know what they are; on top of that it's easy to not notice that they're logarithmic, and I'd bet a lot of people don't even know what "logarithmic" means.
- jiggawatts 6y ago
  In my experience, all of the following words cannot be used in general discourse: Quadratic, linear, logarithmic, exponential, orthogonal, asymptotic, etc... The second you use any of those words, people's eyes glaze over and there's an audible mumble sigh of "Ugh! Maths!" It's sad, but it's the way it is.
  - everybodyknows 6y ago
    I observe that "exponentially", along with "minimal", and "inflection point" are frequently used in the popular press -- wrongly, or at least without understanding of the first, quantitative sense of the term.
    - brokenmachine 6y ago
      Not once have I heard "inflection point" in popular press.
grawprog 6y ago
In all honesty, I know what I'm looking at and I still find it hard to understand by comparison. It's also poor graphing. Graphs should have a purpose and communicate information as clearly as possible. Scales and units should be chosen to most effectively convey information. Logarithmic scales are a poor choice for the information being displayed.
- KarlKemp 6y ago
  The logarithm is appropriate because disease transmission is an exponential process. For a given set of parameters (of measures such as social distancing, mask wearing, weather, etc.) new infections will not rise by some specific, absolute number. Rather, similar environments result in similar rates of new infections as a percentage of existing, active infections.
  - grawprog 6y ago
    But that's not what the graphs are showing. The graphs are showing continuous infections over February, March and April. Those are not unknown future times. Those are past times with existent data. There's no reason not to represent those data as clearly as possible. Which a logarithmic scale does not. Again graphs should serve one purpose. The purpose of those graphs is clearly, by the axis labels, supposed to display continuous deaths over a set period of time. The linearly scaled graph displays this clearly, the logarithmic one does not. If the x-axis displayed into some future time, yes I'd agree a logarithmic scale may be more appropriate. But that would be displaying a graph of predictions at that point, which is something totally different than the two example graphs are showing.
    - plerpin 6y ago
      Simply asserting that graphs should communicate one purpose does not make it so. Multiple audiences require multiple techniques for visualization and analysis. A logarithmic scale communicates the characteristics of an exponential curve better than a linear scale.

mytailorisrich 6y ago

Well log scale is intended to make it easier to read... In general it is used in cases where a linear scale would be unreadable. Your suggestion about changing what is represented in order to avoid a log scale is good but does not solve the root of the issue: many members of the public will not understand the information however it is represented because the concept itself is too complex. It really is a numeracy problem.

redis_mlc 6y ago
Blaming the people you're trying to communicate with is not a winning move. When you look at the 2 graphs side-by-side, as in the article, it's apparent which conveys more meaning (the linear one), unless I suppose you read log graphs all day. The public does not.
- mytailorisrich 6y ago
  Blaming would be to claim that it is their fault for not understanding. Here it is not blame, it is a statement that anything above the most basic maths concepts will stump a surprisingly large number of people. I'm not sure 'surprisingly' is the right word but here it is.
vharuck 6y ago
I've found that, if somebody has trouble understanding a type of statistic (log-scaled, survival rate, confidence interval), it's because they never use them. You could say we should teach these things in high school, but why? So we can effectively communicate data they still won't use? Throwing more math, tech notes, or gentle introductions at the communication problem has never worked for me. What has worked is expressing the concept in the most "real" terms possible. Epidemiologists are worried about exponential growth because it means hospitals will be swamped. That worry should be the topic when communicating with the public. How long until that's projected to happen? Maybe show the linear trend with a horizontal line for capacity and dotted line for a forecast of need. Put a huge red circle around where they intersect. Even better: just write "X days predicted until overrun." Also, charts are terrible for reading data. They're good for comparisons, trends, and distributions. I only use them for exploring or summarizing. Tables are for readable numbers.

_bxg1 6y ago

They take effort to read even when you know what they are; on top of that it's easy to not notice that they're logarithmic, and I'd bet a lot of people don't even know what "logarithmic" means.

jiggawatts 6y ago
In my experience, all of the following words cannot be used in general discourse: Quadratic, linear, logarithmic, exponential, orthogonal, asymptotic, etc... The second you use any of those words, people's eyes glaze over and there's an audible mumble sigh of "Ugh! Maths!" It's sad, but it's the way it is.
- everybodyknows 6y ago
  I observe that "exponentially", along with "minimal", and "inflection point" are frequently used in the popular press -- wrongly, or at least without understanding of the first, quantitative sense of the term.
  - brokenmachine 6y ago
    Not once have I heard "inflection point" in popular press.

grawprog 6y ago

In all honesty, I know what I'm looking at and I still find it hard to understand by comparison. It's also poor graphing. Graphs should have a purpose and communicate information as clearly as possible. Scales and units should be chosen to most effectively convey information. Logarithmic scales are a poor choice for the information being displayed.

KarlKemp 6y ago
The logarithm is appropriate because disease transmission is an exponential process. For a given set of parameters (of measures such as social distancing, mask wearing, weather, etc.) new infections will not rise by some specific, absolute number. Rather, similar environments result in similar rates of new infections as a percentage of existing, active infections.
- grawprog 6y ago
  But that's not what the graphs are showing. The graphs are showing continuous infections over February, March and April. Those are not unknown future times. Those are past times with existent data. There's no reason not to represent those data as clearly as possible. Which a logarithmic scale does not. Again graphs should serve one purpose. The purpose of those graphs is clearly, by the axis labels, supposed to display continuous deaths over a set period of time. The linearly scaled graph displays this clearly, the logarithmic one does not. If the x-axis displayed into some future time, yes I'd agree a logarithmic scale may be more appropriate. But that would be displaying a graph of predictions at that point, which is something totally different than the two example graphs are showing.
  - plerpin 6y ago
    Simply asserting that graphs should communicate one purpose does not make it so. Multiple audiences require multiple techniques for visualization and analysis. A logarithmic scale communicates the characteristics of an exponential curve better than a linear scale.