The phrase "performance gap" refers to the difference or distance between the current level of performance and the desired or expected level of performance in a specific context or situation. Full definition
The annual award, announced today, honors large urban school systems that demonstrate the strongest student achievement and improvement while narrowing performance gaps between different groups based on family income and ethnicity. (edweek.org)
Those are the widest value - growth performance gaps in many years. (sparinvest.eu)
Why then are so many learning professionals still addressing performance gaps with lectures, online presentations, or other theoretical content? (elearningindustry.com)