The MMR vaccine is a measles-mumps-rubella vaccine. Consider the following quote from the article "Review Finds No Link Between Vaccine and Autism" (San Luis Obispo Tribune, October 19, 2005): "'We found no evidence that giving MMR causes Crohn's disease and/or autism in the children that get the MMR,' said Tom Jefferson, one of the authors of The Cochrane Review. 'That does not mean it doesn't cause it. It means we could find no evidence of it.'" In the context of a hypothesis test with the null hypothesis being that MMR vaccine does not cause autism, explain why the author could not conclude that the MMR vaccine does not cause autism.