The study population was the 42 State trooper trainees at the Georgia Police Academy in Atlanta, Ga., all of whom were members of the 1976 through 1977 training group. All trainees are required to take either a speech course or a psychology course for college credit. The sample consisted of one group of trainees who elected to take the speech course and one group who elected the psychology course. Data collection involved the administration of pretests and posttests to the groups. The trainees viewed a film showing a traffic accident, listened to an attorney's questioning relative to the accident, and heard observers' evaluating the trainees on their courtroom competency in testifying. The 16 variables of courtroom competency were content, vocal elements, style, and other presentation characteristics, such as gesturing and eye contact. Data were statistically treated utilizing the Mann-Whitney U test. No significant difference at the .05 level was found between trooper trainees who elected to take psychology and those who elected to take speech in any of the 16 variables observed. Specifically, there was no significant relationship between the speech training course and the courtroom competency in testifying with regard to accuracy of information, precision of vocabulary, standard usage, organization of ideas, articulation, vocal variety, pitch, loudness, rate of speaking, confidence, credibility, enthusiasm, conversational quality, eye contact, posture, and gestures. Footnotes, appendixes, and a bibliography with about 35 entries are included in the study. (Author asbtract modified)