Why usability testing matters
Usability testing means watching real people try to complete tasks with your design. It is named in most design adverts because it is the clearest way to find problems before they reach customers. Expert review, using a list of well known usability rules, is a quick extra check that many teams also ask for.
Running a simple test
1. Prepare. Choose three to five tasks written as real situations: "Your sister in Wa needs 10 cedis of airtime. Send it to her." Do not use the words on your buttons in the task, or you give the answer away.
2. Recruit. Find people like your real users. A few sessions with the right people reveal most of the big problems. Test in the place they normally use their phone if you can: a shop, a market stall, a school.
3. Welcome and consent. Explain that you are testing the design, not them, and that there are no wrong answers. Ask permission to take notes or record the screen.
4. Ask them to think aloud. "Please say what you are looking at and thinking as you go."
5. Watch quietly. This is the hardest part. Do not help, explain or point. If they ask "What do I press?", reply "What would you do if I were not here?" Only step in if they are truly stuck and upset.
6. Take notes. Write where they hesitate, what they say, what they tap and whether they finish. Note exact words.