As a supervisor, your current and former employees may ask you to serve as a reference, whether they are applying for a new job, in the running for a promotion or trying to earn professional certification. Serving as a reference can be a challenge. An employee might not have earned a stellar reference with his mediocre performance. Or, perhaps you just don't know enough about the employee to offer a useful reference. You can strengthen your employee references in several ways.

Provide Specifics

When you receive a call from someone seeking a reference, you might stumble and offer vague words like "reliable" and "responsible" without giving any solid examples to back up your statements. Ultimately, this information is not useful for the person checking the reference. Give specific information about the employee's performance. Tell a story about how reliable or responsible he is. Maybe he offered to come in on the weekend and complete a task so that others could stay home. An anecdote tells more than a vague descriptor.

Be Honest

Ideally, only your strongest employees would ask you to serve as a reference. That way, you could honestly give rave reviews all of the time. In reality, this is not the case. Often, even subpar employees might ask for a reference because you're their only option. If you have true concerns about the employee, share them. You don't want to disappoint the employee, but you also don't want to offer your support if you don't think the employee is right for the position.

Customize

Sometimes, you can write a reference letter, which allows for a more thoughtful reference. Ask the employee about the position for which he is applying. Get the job description or read about the certification, for example. Then, write the reference letter with that in mind. If a former employee is applying for a customer service job, focus on the ways he interacted with customers or clients. His computer skills may not be as relevant.

Tips

Don't speak without thinking -- take time to thoughtfully consider each question, even if you're caught off guard with a phone call. Focus on the employee's responsibilities and his success in completing those tasks. Don't offer sensitive or irrelevant information -- for example, information about the employee's health or family -- during the reference check.