Do education programs for preschool childrent that follow theMontessori method perform better than other programs? A studycompared 5-year-old children in Milwaukee, Wisconsin, who had beenenrolled in preschool programds from the age of 3.

A. Explain why comparing children whose parents chose aMontessori school with children of other parent would not showwhether Montssori schools perform better than other programs. (Infact, all the children in the study applied to the Montessorischool. The school district assigned students to Montessori orother preschools by a random lottery.)

B. In all, 54 children were assigned to the Montessori schooland 112 to other schools at age 3. When the children were 5 parentsof 30 of the Montessori children and 25 others could be located.Those parents who were located agreed to and subsequentlyparticipate in testing. This information reveals a possible sourceof bias in comparison to the outcomes. Explain why?

C. One of the many response variables was score on a test ofability to apply basic mathematics to solve problems. Here aresummaries for the children who took this test:

Group: n x s

Montessori 30 19 3.11

Control 25 17 4.19

Is there evidence of a difference in the population mean scores?(The researchers used two-sided alternative hypotheses.)