Professor John MacBeath told a launch at St Kentigern's Academy, West Lothian:
"It does a whole range of things from paired reading to jazz bands. We've broadened the definition."
The school is one of two Catholic secondaries in Scotland taking part in a major UK study he is carrying out involving 10,000 pupils. St Aidan's High, Wishaw, is the other.
Professor MacBeath placed St Kentigern's at "the leading edge". Pupils even make and sell chocolate in an after-school mini-enterprise. "You can eat study support," he observed.
The four-year study will compare students who have been involved with study support with those who have not. Ministers are hopeful it will demonstrate clear links to exam performance.
Peter Peacock, Deputy Children and Education Minister, emphasised the importance of study support to the Scottish Executive's agenda and pointed to the injection through the Excellence Fund of pound;27 million over three years.
A further pound;23.6 million will come from the New Opportunities Fund for out-of-hours learning schemes.