A teacher interested in determining the effect of a new computer program on learning to read conducted a study. One hundred students were randomly assigned
to one of two groups. The first group used the computer program while the second
group did not. Both groups were tested to determine how much their reading levels
improved. The results for the two groups were compared. What kind of study is this?
(2 points)
1) This is an experiment because a treatment was applied to a group.
2)
This is an experiment because students were able to choose which group to
join.
3) This is a survey because students were randomly assigned to groups.
4) This is a survey because a treatment was applied to both groups,

Aresearch study is studying the effects of a new drug for osteoporosis alzheimer's disease (ad) for women above the age of 65 years. a group of individuals with osteoporosis is randomized into two groups. one group is treated conventionally, and the second group is treated with the new medication. assessments are made at 3, 6, 12, 36, and 48 months. the conventionally treated group is assessed for ad using a serum blood test, and the treatment group is assessed for ad using a pet radiotracer that binds to beta-amyloid plaques. in comparing these 2 trial arms, the authors of the study may encounter which type of bias? a. selection bias on the risk of developing b. measurement bias c. confounding bias d. recall bias e. lead-time bias