As the academic semester ends and graduation approaches, the hiring season is in full swing. For over four decades, I have been training and working with undergraduates at Cornell University. To my joy and some pride, among my former students are well-known corporate leaders, public figures, and an array of entrepreneurs. I sometimes reflect on the qualities of my most successful students, and I am somewhat dismayed to think that if some of them were entering the job market today, they would have fallen through the cracks.

As there is more emphasis on mass hiring through recruiting agencies, there is a greater obsession with strong signals rather than weak signals. The alma mater, the grades, the activities, and the cookie-cutter elements that are easily measured and give some benign threshold of achievement, but may be predictive of very little. I’ve found that in my experience with students, the weak but persistent signals can speak more to a person’s character and potential than strong signals. There are several weak signals that are never quite captured in the resume, interviews, or tests, but can be discovered with a comprehensive conversation with their mentors.

Tenacity. The one trait that most of my successful students have in common was their tenacity. These students who took on special projects and sought out opportunity. They went beyond the core course requirements, and involved themselves in extended research and volunteer projects with focused intention.

Spark. These students shared a type of irreverence, a casual indifference to the way things are or should be. Each one had a sparkle. This subtle spark of quickness, intelligence, and wit differentiates the good from the best.

Trust. These students understood moral parameters, knew that need to share credit, and had the commonsense to distinguish acceptable and unacceptable behavior. While ambitious, it was bounded by a core understanding of the rules of the game.

Leadership. These students had taken the lead on projects. They could assemble and motivate a team of researchers. They could map out what needed to be done, and they could follow up to make sure that the work was done.

Humility. Most of these students exhibited a degree of humility. While not lacking in ambition, they had a deep sense of their limitations, which did not enhance their competitive insecurity but strengthened their tendency to work with others.

Last week I was asked to give a reference for a student who had graduated five years ago. He had a good job, but was looking around for new opportunities. While I told the recruiter he was not the best analyst or the very best technocrat, I re-framed the discussion on what I consider to be the four prerequisites of a future leader: tenacity, spark, trust, leadership, and humility. He starts in two weeks.

My advice to organizations seeking to hire the best is to have a comprehensive conversation with the college mentors of their job candidates. There is the battery of questions that have to be asked to fulfill bureaucratic requirements, but put down the list for a moment and go off script. Take the time to dig a little deeper and learn about those things that aren’t immediately evident and cannot be readily measured. The reward will be having some great people on the team.