Sometimes, just the odd phrase catches your eye in a management book. What, for example, would count in school as a "high-leverage task"? Getting Darren to come out of the toilet after Mrs Hardball has shouted at him?
In fact, Geoff Smith's explanation, which is that "high-leverage tasks are investments of time to save time in the future", makes good sense. The pressures in school are such that too little attention is paid to that sort of strategic thinking, and the neat label is as good a way as any of highlighting the issue.
The book is aimed at those who lead teams of independently minded professionals - teachers, lawyers, architects - where the challenge is more to motivate and point the way than to crack the whip.
The advice it gives has the ring of the real world. I like, for example, Smith's warning to avoid making facile judgments about how people behave in meetings. "Some of us think that people are uninterested or withholding information, when in fact they are working things out in their head. Others have the impression that someone is uncertain or inconsistent when that person is thinking aloud."
You knew that, of course, but there are other leaders and managers who impatiently forget it.