A biologist wonders if the life span of bats will be affected by two new food sources from invasive species moving into an area. To conduct the experiment, the biologist needs three treatment groups: a group where the diet will not include invasive species (control), a group where the diet will include one invasive species (treatment group 1), and another group where the diet will include the other invasive species (treatment group 2). The biologist chooses the first cloud-free night and catches the first 18 bats that fly out of a cave. The first six bats will be the control group, the second six will be treatment group 1, and the last six will be treatment group 2.
Which component is missing from the biologist’s process?
The biologist should have chosen a random night to catch the bats.
The biologist did not randomly assign the bats to the treatment groups.
The biologist did not allow each bat the same chance to be in each treatment group.
The biologist should have used random sampling when deciding which bats to catch.
answer is b
