Change Blindness

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Presentation: Paul CurzonChange Blindness: Milan Verma & Peter McOwan,

Queen Mary University of LondonDesign solutions: Harold Thimbleby / CHI+MED at Swansea University

With support from Google, D of E and the Mayor of London In collaboration with CHI+MED

A joint research project with Swansea, UCL and City Universities

Change Blindness• In the following images something changes

every time the picture flashes• How quickly can you see it?

• The first is designed to be easy to see• The second should be much harder

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What’s happening here?

What’s happening here?

Just because it is on the screen

…doesn’t mean the nurse will see it- even if he’s looking

As a computer scientist you must design it so they do!

Medical device design?

Based on a real case …• A nurse intended to enter a dose of 5.5mg/hr• She pressed the decimal point twice typing 5 . . DEL 5

– The device deleted both decimal points.

– The nurse didn’t notice!– 55mg/hr was actually entered– The patient was given a x10

overdose & died.

• The nurse went to prison – its easy to blame the operator

• What should a device do if an invalid number is typed?

A simple improvementWhy don’t calculators do that???

Think again…Is there a completely different way?

Digit keypad is fastest, but is there a safer way?

• 5-key keypad is safer– Fewer big mistakes made– Eyes on screen all the time– Not on the keys

Lessons• People make mistakes

– you have to design the system both • to prevent it and • to help people recover

• Understanding people matters!– To computational thinking problem solving– It’s important that both the algorithm and

interaction design work well!

Change Blindness by Milan Verma & Peter McOwan, Queen Mary University of LondonDesign solutions by Harold Thimbleby and the Swansea CHI+MED team

More supportOn our website to support this session:• Activity sheets • Story sheets• SlidesDetails of more worskshops/courses• free unplugged sessions• subsidised courses (e.g. GCSE programming)

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Thank you!

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