Adouble-blind study is sometimes needed because

a. may have expectations that affect their observations.
b. cannot control every variable outside a laboratory.
c. may not have time for a longitudinal study
d. are bound by a code of ethics

Which of the following is an example of negative reinforcement? a.marty knocks over his mother's prize fern so she gives him a time out. b.gwen mows the lawn and her dad takes her out for ice cream. c.tara takes an aspirin, and her headache begins to go away. d. peter comes in late from his lunch and is fired from his job.

Which of the following is characteristic of an ethnic religion? a.) the religion has spread far beyond its hearth. b.) the religion is not focused on a particular region. c.) the religion is centered on the message of a prophet. d.) the religion attempts to appeal to people everywhere. e.) the religion does not actively try to convert others

Do you want free brainliest and free points? answer this drivers ed question correctly and ill give you both : ) how can you count following distance? a. look for a moving object and count the seconds it takes for you to pass it after the car you are following has passed it. b. look for a stationary object and count the seconds it takes for you to pass it after the car you are following has passed it. c. look for the rear wheels of the car in front and count the number of rotations. d. look for the stripes on the road and count them as you pass by.