I gave him a scenario of him standing at Slussen with the goal of taking the ferry to Skepsholmen. I showed him our prototype and told him to tell me what he was thinking while looking at it, I also told him that the screen was located in the queue while wating for the ferry to arrive. The image he was looking at was the first one in our blog post called "Prototype".
The first thing he said was that the green dot is our current position and the red one is probably the ferry. Then he said that it seems like this ferry will go to Djurgården (green line) so i'll wait for the next one which will go via Skeppsholmen. I told him that the ferry won't go via Skeppsholmen unless you tell the personnel and that it was a touch screen. He then pressed at Skeppsholmen and i switched to the second image in the "Prototype" post. He then said that he was unsure if the ferry would go via Skeppsholmen since the text still said "Djurgården" and not "Djurgården via Skeppsholmen" which is typical on SL-screens. He also pointed out that the green and gray line look quite similar.
This made it clear that we have to improve on a few things:
- "the red dot is probably the ferry".
- Not obvious that you have to/able to press Skeppsholmen on the screen.
- When you go via Skeppsholmen the text do not change to "via Skeppsholem".
- The green and gray line look quite similar.
I think that think-aloud evaluation is a great method to find where users get stuck and don't know what do do next. Since they always have to say what they think you can later figgure out why they thougt something would work a certain way and improve the design. A drawback is that it's not always easy to say what you think, users may do somethig, can't explain why and just move on.