"Employer's hiring behavior specialists are looking for candidates with the educational background and interpersonal skills to properly instruct patients with behavioral disabilities. In an interview, be ready to speak to your background in behavioral psychology and any experience working with children or disabled individuals. Be prepared to explain how you would handle difficult patients with aversions to learning as well as what corrective methods you would use."
They asked what you know about ABA and what experience you have with it. They also try to determine if you are qualified both physically and mentally for working with this special population. They need to know that you will be able to work with students that potentially can be violent and how you would react to them.
I did not have any experience with ABA but had researched it. I let them know a brief overview of it.