The characteristics of the two groups A researcher wants to know if eating a mint affects
whether people can distinguish between two popular
orange juice brands. To conduct an experiment, the
researcher places 50 participants in two groups. The
treatment group will eat a mint before drinking a juice,
while the control group will not eat a mint before
drinking. Then the participants will guess the juice
brand. To select the groups, the researcher labels each
participant with a number and selects slips of paper
labeled 1-50 from a bowl at random. The first 25
participants whose numbers are selected will be the
treatment group, while the other 25 will be the control
group.
O should be roughly equivalent because both groups
will have 25 participants.
should be roughly equivalent because the
participants were labeled and then randomly
selected for the groups.
might not be roughly equivalent because one group
may contain people that drink more juice than the
other group
O might not be roughly equivalent because one group
may contain more people that prefer a particular
juice brand.