No. This is a common confusion in the field. A certificate of completion simply shows that you finished a training program. Certification shows that the certifying body is guaranteeing that you are qualified: that you have demonstrated the knowledge and abilities that a scientifically-designed process has shown to be necessary to provide a service. While a certificate of completion is certainly a valuable document to prove your training, it is not the same as a certification. Think of it as the difference between a doctor who has graduated from medical school and one who has passed her Board exams.