28. Some Types of Mental Processing Are More Challenging Than Others

Nota:

• Each load uses up a different amount of mental resources. 
• TAKEAWAY: When you design a product, remember that making people think or remember (cognitive load) requires the most mental resources.    

1. MAKING TRADE-OFFS

   Nota:

   • TAKEAWAY: Look for trade-offs, for example, where you can reduce a cognitive load by increasing a visual or motor load.
   1. USE FITT’S LAW TO DETERMINE MOTOR LOADS

      Nota:

      • Although motor loads are the least “expensive” of the three loads, you often want to reduce them. One way to reduce the motor load is to make sure that the targets you’re asking people to hit aren’t too small or too far away, for example, when you ask them to move a mouse across a screen and click a button or a small arrow on a drop-down box to show a list of choices.               
      • TAKEAWAY: Make sure your targets are large enough to be easily reached. 
      1. SOMETIMES YOU WANT TO INCREASE LOADS

         Nota:

         • For example, to grab someone’s attention you might add visual information (pictures, animation, video) and thereby increase the visual load of the product.    
         • Evaluate the loads of an existing product to see if you should reduce one or more of the loads to make it easier to use.    
         1. Evaluate the loads of an existing product to see if you should reduce one or more of the loads to make it easier to use.
   2. Clicking is less of a load than thinking.
2. Visual

   Nota:

   • Things you’re looking at on the screen 
   • You use up more resources when you ask people to look at something or find something on a screen (visual) than when you ask them to press a button or move a mouse (motor). 
3. Cognitive

   Nota:

   • Things you’re thinking about and remembering  Most expensive resource load
   • You use up more by asking them to think or remember or do a mental calculation (cognitive), than when you ask them to look at something on a screen (visual)    
4. Motor

   Nota:

   • Buttons you are pressing, mouse movements, and typing Least expensive resource load