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ELI5 Yahaaa

Seeing beats reading

Why Draw Numbers as a Picture?

A graph turns a list of numbers into lengths your eyes can compare instantly.

A list of numbers?Read and remember eachoneThe same as a graph Compare at a glance
The numbers are identical. Only one is instantly readable.

  1. Step 1 of 5

    Lists make you hold numbers in your head.

    1?Read eachnumber2 Hold them inmind3 Only thencompare

    To find the biggest value in a column you must read every entry and remember the largest so far. That is real work for your memory.

  2. Step 2 of 5

    A graph turns numbers into lengths.

    Three becomes a shortbarSeven becomes a tall one

    Each value becomes a bar of matching height, and comparing heights is something eyes do instantly without any conscious effort.

  3. Step 3 of 5

    Different questions want different graphs.

    Bar chart Comparing separatethingsLine graph Change over time

    Bars compare separate things. Lines show change over time. Choosing the wrong one hides the very pattern you were trying to show.

  4. Step 4 of 5

    The axis has to start at zero to be honest.

    Axis from zerohonestproportionsAxis from 90tiny gaps lookhuge

    Starting the scale partway up makes small differences look enormous. The bars stop being proportional to the numbers they represent.

  5. Step 5 of 5

    A good graph makes the answer obvious.

    Pick the question firstwhat are youshowing?Choose the matchingshapebars, lines orpartsStart the axis at zerokeep it honest

    If someone has to study a chart to work out what it says, it has failed. The point should land before any of the labels are read.

    William Playfair invented the bar chart in 1786 because a list of Scottish trade figures was impossible to compare by reading.

The short version

Graphs work because eyes compare lengths instantly, but only when the right chart is chosen and the axis starts at zero.

Try it yourself

Write down your last seven days of screen time, then draw them as bars. The pattern jumps out in a way the list never did.

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