‘The Psychopathology of Everyday Things’

'Psychology of materials' people judge what to do with something on the material its made from

Affordances are the percieved and actual properties of something

Something that works by affordances shouldnt need instructions as the affordance means the user will already know what to do

'False Causeality' the idea that if something goes wrong by coinicedence or by something unrelated the user thinks they are responsible

Example 1: The thermostat dial in my house requires no instructions as the fact that it is a dial means it is clear how to use it due to its affordance

Example 2: A blender that i used to have had a simple one button with an on/off function, it required no instructions as the affordance of just having a one button to push makes it obvious what to do

Correct parts should be visible

Lack of clues on what to do make it hard for the user to do what they want

Functions are often features but so hard to find or use that users just ignore them

Poor Instructions make it hard for the user to learn what to do

Example 1: Earlier in the year we had a washing machine in our house that worked by selecting a number on the dial, yet there was no obvious indication on what number did what

Example 2: I once had a microwave that had no obvious "start" button, you could easily pick the time and settings but it was hard to work out how to actually start the microwave

Sending back to the user informtion on what has been done

Gives the user confirmation they have done what they intended

No feedback means the user has no idea if what they wanted to do has happened, rendering the device useless

Example 1: The washing machine in my house gives no feedback when they settings are changed, this is bad as because there is no feedback I don't know if what i intended to do has been done

Example 2: I have a touchscreen phone, everytime you touch a button the phone vibrates a small amount to let u know the button has been pressed, if the user touches a part of the screen that doesnt do anything there is no feedback and the user will know they havnt done what they intended.

The sheer number of everyday objects/devices

Everybody has problems using some devices, even experts

Conceptual Models

A model idea on what to do already

When things go wrong, conceptual models are harder to follow/rely on

Mapping is the realtionship between two things such as a set of controls and the function they perform

The more complex the functions/device the more confusing the mapping is for the user to understand

Example 1: The mapping on the washing machine in my house is bad as you change the settings on the dial but there is no way off seeing what they change has done