Job seekers looking to validate their qualifications often ask previous supervisors and colleagues to vouch for them by writing letters of reference. If you've worked with or supervised a teacher's aide, and have the pleasure of writing a letter on behalf of someone you believe was effective and competent at her job, construct a well thought-out letter to strengthen her case for showing she's a qualified candidate.

Make Sure You Are Allowed

Many employers prohibit supervisors and colleagues from providing references for current employees. Check with your school's human resources department to determine whether you -- as a supervisor or colleague -- have permission to vouch for the aide's qualifications. If your school authorizes you to write such a letter, you may have to provide the HR department or your manager with a copy of your draft to ensure that you're providing your individual perspective and not disclosing inappropriate information about the aide's employment status or performance ratings.

Explain Your Relationship

The first paragraph of your letter should describe your relationship. Explain whether you are a colleague, peer or supervisor. Provide information about how long you worked together and the name and location of the school. If you know anything about the aide's selection for that job, include that as well. For example, if you were on the interview panel when she first applied to be a teacher's aide, indicate your impression of her ability to articulate her qualifications.

Evaluate the Aide's Skills

Tell the reader whether you believe the aide has the necessary skills to become a teacher or teacher's aide. For example, you could write, "Mary exhibits several professional competencies in such areas as assisting the lead teacher with English-composition lesson plans and evaluating student assignments. In addition, she is well-versed in American and British literature, which are subjects our school began offering to advanced placement students last fall. Mary was instrumental in developing those two new courses."

Elaborate on Aide's Teamwork Skills

Address the teacher's aide's ability to work collaboratively with other aides and the lead teachers to whom she reports. Write a brief example and comment on her conscientiousness in working as a member of a team. If appropriate, include a statement about whether she is capable of taking on a leadership role. In addition, write about her ability to engage parents in promoting their children's academic goals.

Assess Aide's Ability with Students

Prospective employers are interested in how well teachers' aides work with students and whether their students value their guidance. Give your perspective about how students interact with her. Base these statements on your personal observations; you needn't ask students for their opinions to assess the aide's effectiveness in and outside the classroom. Include a statement about the aide's work ethics and professional code of conduct, such as her commitment to maintaining professional collegial and teacher-student relationships.