6. A department store uses a 7. A researcher observes and market research survey to records the behaviors of children determine the types of products on the playground before lunch various consumer groups are and after lunch. buying Choose all that apply. Choose all that apply The characteristics that best The characteristics that best describe observational studies describe surveys are: are Answer choices: Answer choices: Work with a wide variety of Work with a wide variety of formats formats Involve studying subjects in their Involve studying subjects in their environment, which is not environment, which is not controlled in any way controlled in any way May collect either facts or Are not used to prove cause and opinions effect relationships 8. A biologist takes 9. A researcher is testing to see if measurements to see if a new a newly formulated eye drop plant food affects the rate of improves vision. plant growth Choose all that apply. Choose all that apply. The characteristics that best The characteristics that best describe this method of data describe surveys are: collection are: Answer choices: Answer choices: Allow the researcher to change Allows the researcher to change one variable in some way one variable in some way Involve studying subjects in their Is not used to prove cause and- environment, which is not effect relationships controlled in any way Determines whether the Determine whether the researcher's change had an researcher's change had an effect by taking measurements effect by taking measurements after the change after the change