1. As a child grows in height from infancy to preschool, his or her vocabulary also

Explanation:

When doing the experiment, the independent variable is the variable that manipulates to see if it affects behavior the variable being vitamin E. While the dependent variable being the effect that the independent variable has on the memory, and extraneous is everything except the independent variable (vitamin E) that are influenced in the results that changes the dependent variable, things that can be controlled. In this experiment it is important to have random samples to generalize the population. Something like sleep or age may be controlled, as it could affect memory because it is a random sample and it represents the population being studied, giving the population an equal chanceof being selected to participate in the study. The control groups will be set up randomly by age and the amount of sleep, with a group who will receive vitamin E and the other group receiving placebo, with each participant not knowing what group they are in. In single blind studies, the experimenter is aware of who belongs to the control group and the experimental group. In double blind studies, the experimenter is not aware of who belongs to which group. In this experiment we will be using the single blind study allowing each controlled group to be equal seeing how well they will do on a memory test. Being that each group will have similar expectations, with placebo not being vitamin E, to measure the effects of the groups. If the control group is given a placebo, then it’s assumed that all groups (control and experimental) are equal in terms of their expectation, and so any differences in behavior (e.g. memory) can be attributed to the actual amount of vitamin E consumed, and not to expectation