How to differentiate between "Engaged" and "potentially Disengaged" employees?

An engaged employee is one who is passionate about their job, is knowledgeable about the company and connects with the business strategy, taking a keen interest in their role and assigned tasks, consistently making a concerted effort to accomplish them with confidence.

A disengaged employee is someone who lacks most of the above, for an extended duration.

A potentially disengaged employee is someone who lacks in a few of the above, for an extended duration.

An actively disengaged employee is the exact opposite of the above description.