Dr. J оnce sаw а pаtient whо was оnly 5 years old and very violent. He punched Dr. J in the nose, bit his teacher's ear almost completely off when angry and frequently hit his mother and father. The young child's behavior was out of control. Dr. J decided, against his supervisor's advice, to get the child a CAT Scan. The CAT scan revealed that he had a large tumor in the prefrontal cortex of his brain that went undetected for years and eventually ended his life. If Dr. J told his students that this case study should be used to guide decision making with all patients who are hyperactive and impulsive and that all 5-year-olds with these symptoms should receive a CAT scan, how would you rate the internal validity and external validity of these single case conclusions?