A researcher is interested in the effectiveness of a particular method of studying for a math test. Twelve students are randomly assigned to each of two groups, with one group receiving training in this study method, and the other encouraged to study in their own way. Each student then takes a test on the material. What is the null hypothesis in this situation?

Select one:

a.

H₀: _treatment= 0

b.

H₀: _control< .05

c.

H₀: _treatment= u_control

d.

H₀: _diff = 0