Class Practices for Lecture on Chapter 9 Factorial Designs A researcher was interested in gender differences in students' writing skills and the impact of writing programs on improving writing skills. 40 students (20 boys & 20 girls) were randomly assigned to receive the ACCESS writing program for a year and another 40 students (20 boys & 20 girls) were randomly assigned to receive a traditional writing program. At the end of the year, all students took a writing test with scores ranging from 1 to 100. All the mean differences were found significant, p