. In an experiment, the _____ group receives no manipulation

Your text discussed a well-publicized study showing a positive correlation between young children sleeping with a nightlight and the children later becoming nearsighted to illustrate the point that:

a. correlations greater that +50.00 are easier to interpret than those less than +50.00 b. small changes in children's environments can often have substantial changes in children's preferences (e.g., whether they read just for fun) c. the same environmental stimuli that can have a large effect on children younger than 3 often have no effect on children older than 5. d. seemingly straightforward causal inferences of causation based on correlational data often prove to be wrong

In Asian countries,

A) teachers emphasize drill in computational skills more than in U.S. schools. B) use of the metric system helps children grasp place value. C) teachers spend much less time on underlying math concepts than in U.S. classrooms. D) multidigit problems are introduced later than they are in U.S. schools.