I am applying this fall (early). I already have two teacher recs, and I was wondering if that “additional” rec would be helpful. The rec would be written by my employer/engineer-mentor in my internship with a wafer manufacturing company. He had offered to write me one.
I think additional recs that add a different perspective on an applicant are worthwhile. Likely your employer can expound on some traits/characteristics/qualities you have that are different from your teachers.
Good luck!
As long as your employer can offer something else that your application doesn’t already show, an additional Rec letter would be worthwhile. Just keep in mind that admissions officers have pages of applications to read, so unnecessary material may lengthen your application but diminish its strength.
Have talk with your mentor about exactly what you think might be helpful to you to include in his/her rec letter since you will want to highlight qualities different from those that your teachers will highlight. Many employers are unfamiliar with what a good college rec letter looks like and they tend to write letters that sound a lot like recommendations for jobs - without the hyperbole that has become the norm for college rec letters, for example. If your mentor can compare you to others with whom he or she has worked ("Of the 10 interns I’ve had over the past decade, Susan has been the most creative and insightful…) that is helpful. If he/she can provide concrete examples of some particular work-related achievement and assess the level of complexity and sophistication, that would also help. What you don’t want is one more piece of paper that says what’s already been said about you, however enthusiastically.
That said, ask him to keep a copy of the letter on file for you. You never know when you might need another letter of recommendation for something else…a scholarship, another internship, etc…