Two groups of programmers solve problems - what kind of experiment?

Question

Project management

Two groups of programmers were given the same two (or three) tasks, but one was asked to do sequentially: first one, then the second, and the other group was asked to do both tasks at once, in parallel.
As a result, it turned out that the sequential group worked more efficiently, and the parallel group spent 25% of the time switching between tasks.
Please tell me where to find a link to the study itself, where and when it was carried out and by whom?

Answer 1

find at work. This task is like a mammoth guan - a hundred years in the afternoon: when you need to do it consistently, any fool will do it faster, any PM knows that
problems begin when they sequentially sail NOT THERE, and there "not there", that you have to start everything from the beginning, and not from any stage
hence the hypothesis testing groups, and agile / scrum, and waterfalls and much more, but there is still no silver bullet,
and if something somewhere turned out a little more or less - always turn on your head and look for the other side of the coin