STEPS AND CHOICES
Flowchart
Boxes for actions, diamonds for decisions and arrows for the order things happen in.
Is it the right one?Start
A GUIDE TO VISUAL THINKING
Stuck on it?
Draw it.
A few boxes and arrows can untangle what a page of notes cannot.
Diagrams put related facts side by side, so you search less and see more. Drawing one also helps you remember. Here is how to choose the right kind, and how to sketch it so other people can read it too.
Plain English, with the sources linked.
SKETCHthen think
Find your diagramKeep in mind
- Pick the shape
- Sketch it rough
- Label it clearly
- Boxes before sentences
THE SHORT ANSWER
Match the shape
to the question.
Most everyday problems fit one of
a handful of simple diagram types.
THINGS THAT OVERLAP
Venn diagram
One circle per group, so what two things share sits right there in the overlap.
Why pictures help
THINGS IN ORDER
Timeline
One line with events spaced by date, so gaps and clusters jump out.
Sketch one nowA QUICK DIAGRAM PICKER
Which diagram
fits your problem?
Pick what you are trying to show. The picker suggests a simple diagram that suits that kind of information.
These are rules of thumb, not a standard. Plenty of problems mix two shapes, such as a timeline with a flowchart hanging off one step.
TWO FINDINGS WORTH KNOWING
Draw it once,
see it twice.
Pictures help when you take information in,
and drawing helps when you make it your own.
Often 2× more
Words recalled, drawn vs written
In University of Waterloo experiments, people who drew a word for 40 seconds often recalled more than twice as many drawn words as written ones. Even 4 seconds of drawing gave a large advantage.
DRAWING TO REMEMBER · 2016
11 of 11
Tests favouring words and pictures
Richard Mayer’s summary of the multimedia principle found that learners given words and pictures beat those given words alone in all eleven tests, with a median effect size of d = 1.39.
WORDS PLUS PICTURES · 2009
Neither finding needs artistic skill. The drawings in the memory study were quick sketches, and a diagram only has to be clear, not beautiful.
SKETCH ONE NOW
Four habits for
clearer diagrams.
Step 1
Write the question at the top
One line saying what the diagram should answer keeps it focused and tells you what to leave out.
Step 2
Sketch it rough first
Use pencil or sticky notes so you can move boxes around. Neatness can wait until the shape is right.
Step 3
Label, do not just colour
Put a word on each box or line. If colour carries meaning, add a shape or pattern as well so it still reads in black and white.
Step 4
Keep lines dark and few
Use strong contrast against the background, keep arrows flowing one way where you can, and avoid crossing lines.
DIAGRAM FACTS
Five things worth
knowing.
Location does the work
Larkin and Simon’s 1987 paper in Cognitive Science argued that diagrams index information by location, so related facts sit together and need less searching.
A few seconds of sketching counts
In the 2016 Waterloo study, even 4 seconds spent drawing a word gave a large memory advantage over writing it.
Flowchart symbols have a standard
ISO 5807, published in 1985 and confirmed again in 2019, defines symbols for data, program and system flowcharts.
Colour alone can mislead
Red-green colour vision deficiency affects about 1 in 12 men and 1 in 200 women, so meaning carried only by red and green is lost on many readers.
Lines need contrast too
The web accessibility guidelines (WCAG 2.1, criterion 1.4.11) ask for a contrast ratio of at least 3:1 for the parts of a graphic needed to understand it.
QUICK QUESTIONS
Diagrams, answered.
Short answers to the questions people ask most.
Why do diagrams make problems easier?
In a classic 1987 paper, Jill Larkin and Herbert Simon argued that a diagram groups information by location, so related facts sit next to each other. That cuts down the searching and remembering you have to do when the same facts are written as a list of sentences.
Does drawing something help you remember it?
In University of Waterloo experiments published in 2016, people often recalled more than twice as many words they had drawn as words they had written out. The advantage held even when they had only 4 seconds to draw.
Is there a standard for flowchart symbols?
Yes. ISO 5807, first published in 1985 and last confirmed in 2019, defines the symbols and conventions for data, program and system flowcharts. For everyday use, boxes for steps, diamonds for decisions and arrows for flow are enough.
Which colours should I avoid in a diagram?
Do not rely on red against green alone. Red-green colour vision deficiency affects about 1 in 12 men and 1 in 200 women. Add labels, patterns or different shapes so the meaning survives without colour.
Do words and pictures together really work better?
Richard Mayer’s multimedia principle states that people learn better from words and pictures than from words alone. In his summary of eleven tests, all eleven favoured words plus pictures, with a median effect size of d = 1.39.
Destination
Where the facts come from
- Need to remember something? Better draw it (Wammes, Meade and Fernandes, 2016)University of Waterloo
- Why a diagram is (sometimes) worth ten thousand words (Larkin and Simon)Cognitive Science, 1987
- Multimedia principle, in Multimedia Learning (Mayer, 2009)Cambridge University Press
- ISO 5807:1985 Documentation symbols and conventions for flowchartsISO
- Understanding WCAG 2.1 success criterion 1.4.11: Non-text contrastW3C
- Colour vision deficiency (colour blindness)nidirect (NI government)
Updated