"Professional" implies an attitude of commitment to the job and to the profession.  Most HT's and HTL's have professional attitudes.  Some doctoral level personnel don't.

Degrees and certificates are both credentials.  Both are valuable.  Certificates tend to be more practical and more uniform in quality.  Much of my graduate education came from an HT.  (Nick Roman had only an A.A., but he was an inspired and inspirational tinkerer in the lab.)

 

                               Allen A. Smith, B.A., B.S., M.A., Ph.D.

                               Professor of Anatomy

                               Barry University School of Graduate Medical Sciences

                                       Podiatric Medicine and Surgery

                               Miami Shores, Florida