Tommy told the class that his science fair project proved that drinking three cans of soda each day will make you taller. Tommy explained that he measured his height at the beginning of the experiment and then drank three sodas each day for the next four weeks. At the end of the four weeks Tommy claimed he had grown 10 centimeters. What is needed to show that Tommy’s findings are valid?

his experiment being printed in a science journal

his procedure being reviewed by a group of his peers

his procedure being repeated with the same or similar outcome

his procedure read by scientists not involved in the experiment