Norman Chapter 2 Psychology of Everyday Actions Jeff Offutt http://www.cs.gmu.edu/~offutt/ SWE 205 Software Usability and Design

Making Mistakes When people make mistakes with UIs, they either: Blame themselves for not paying attention or Blame themselves for being incapable They seldom blame the UI ! This is deadly in math, because every subject builds on the previous Once we fall behind, we think we’re too dumb for math EVERYbody falls behind sometime 23-Feb-19 © Jeff Offutt

Growth Mindset All students fail sometimes Fixed mindset Some come back stronger and more determined Some give up Carol Dweck Fixed mindset I believe my intelligence and ability to learn is fixed and cannot change Growth mindset I believe that hard work can make me more intelligent and better at learning Growth habits : Being organized, asking questions, practice, eating well, sleep 23-Feb-19 © Jeff Offutt

Models Vs. Reality A B C A little physics says that the ball keeps its horizontal motion even after being dropped Naive guesses are A or B 23-Feb-19 © Jeff Offutt

Do NOT assume users are perfect “Stuff” Happens If an error is possible, someone will make it Good UI designers must assume all possible mistakes will happen Design to minimize the chances of mistakes Design to minimize the consequences of mistakes Design to maximize recovery from mistakes Do NOT assume users are perfect 23-Feb-19 © Jeff Offutt

Helping Users Choose Action Visibility : The user can see the state of the device and how to use it Good conceptual model : The device works the way the users expect Good mappings : Users can see relationships between actions and results, controls and effects, and state and appearance Feedback : The device tells the user what happened at every step 23-Feb-19 © Jeff Offutt

When something seems easy to use it was probably hard to design Summary When something seems easy to use it was probably hard to design 23-Feb-19 © Jeff Offutt