Anyone wants to be my friend?

In which research method does a researcher change the value of one variable to determine how the change affects another variable? a. experiment b. observational research c. survey d. case study

Which two statements regarding graduated driver licensing are true? select all the correct answers. gdl new drivers gain skills under low-risk conditions. gdl new drivers gain skills under high-risk conditions. gdl laws are the same across states. gdl laws vary across states. gdl does not need parental supervision and coaching.

Dr. robbins wants to know if there are different opinions regarding the value of public school education between native americans who have at least one relative who attended indian boarding school and native americans who have no family experience with indian boarding school. dr. robbins contacts 35 native american participants in each group. he wants each group to include younger as well as older adults, and a mix of male and female participants. he asks each person to complete a survey about their attitudes toward public education. the design of this study is: