The 1940 census had questions not asked on previous censuses. The site Census.Gov has the actual census used in 1950. Take a look at what is asked in the 1950 census. Like the 1940 census, extra questions are asked for a “sample” household. One of my favorite questions from the 1940 census was what grade had been completed by the person. That has been moved to the “sample” section with a slight change. The last grade attended and a second question, did the person complete the grade. Site: http://www.census.gov/history/pdf/1950_population_questionnaire.pdf