...
- how TT scores relate to UT scores, why 65+ is good, and the role of visual design, nav aids, content, etc. in eventual success rates. Lisa Fast’s graph?
What the overall success rate doesn't tell you is how much the success rate of the individual tasks varied. For example, a 60% overall score may mean that all tasks hovered around 60%, or that half your tasks were 90% and half were 30%. To find out, you need to drill down to the task level - see Task success rate later in this chapter.
Overall directness (backtracking)
...
While the overall directness score gives you a rough idea of how clear and distinguishable your headings are, you’ll need to drill down to specific tasks to determine where the most backtracking happens. For more on this, see “Where people backtracked” Directness – where they backtracked later in this chapter.
Overall speed (time taken)
...
This is a very rough measure, however, and to make sense of it, you’ll need to drill down to see which tasks (or specific areas of the tree) are slowing down your participants. For more on this, see “Where people slowed down” below Task speed - where they slowed down later in this chapter.
Keeping your study brief
...