Job skills vary from industry to industry, but there are some universal qualities that entrepreneurs should always seek out when they’re boosting their company’s headcount. William Sahlman, a professor at Harvard Business School, runs down the best qualities for prospective workers in this entrepreneur though leader lecture, given at Stanford University.

The key things to look for, he says, are integrity, references, attitude and adaptability. It’s critical, he adds, to look beyond the resume.