The trail making test asks you to connect a set of scattered dots in order, as fast as you can, and it comes in two parts. Part A is numbers only: tap 1, then 2, then 3, up the chain. Part B alternates numbers and letters, so you go 1, A, 2, B, 3, C and on. It is one of the most widely used attention tasks because it packs searching, sequencing and, in Part B, switching into a run that takes under a minute.
What each part measures
Part A is mostly about visual search and processing speed. You scan the board, find the next number and move to it, over and over. There is one track to follow, so the main thing being measured is how quickly your eyes and hand work through it.
Part B keeps the searching but adds a second track. Because you alternate between numbers and letters, you have to hold two sequences in mind and switch between them on every step. That switching is the harder job, which is why almost everyone finishes Part B slower than Part A. The size of that gap is often the more telling number, since it hints at how smoothly you change mental gears.
How to read your time
Your raw time depends on things that have nothing to do with you: a bigger screen means more travel between dots, and a wider spread of dots means more searching. For that reason the time is most useful as a comparison against your own past runs on the same screen, rather than against anyone else.
A clean run with no wrong taps also beats a faster run riddled with mistakes. Tapping the wrong dot does not stop you here, but it is counted, and a tidy run usually reflects steadier attention than a frantic one.
How to get a better time
A few habits help. Glance across the whole board before you start so you have a rough sense of where the early numbers sit. Keep your eyes moving ahead to the next target rather than fixing on the one you just tapped. On Part B, say the sequence quietly to yourself, “one, A, two, B”, so the alternation has a rhythm and you are less likely to skip a step.
Warming up matters too. The first run on a fresh board is often your slowest, so a throwaway attempt before the one that counts usually gives a better time.
Try it yourself
The trail making test lets you run Part A or Part B and saves your best time for each. Try Part A to get a feel for the search, then Part B to add the switching, and compare how much the second track slows you down. If you enjoy attention challenges, the Stroop test measures how well you push past conflicting information, and the Schulte table trains the same kind of quick visual search.