Which component is missing from the researcher's process?
A researcher is comparing three new formulas for
grass killer. To conduct the experiment, the researcher
purchases 30 pieces of sod from various vendors to
use in the study. To create the three treatment groups,
the researcher numbers the pieces of sod 1-30 and
places the numbers in a hat. The researcher randomly
selects 10 numbers, making sure to mix the numbers
between each selection, and then repeats that process
one more time to select the pieces of sod in the
experiment
The researcher did not use randomization when
assigning the groups.
The researcher should not have purchased sod
from different vendors.
The researcher did not assign the chosen pieces of
sod to treatment groups.
The researcher should have randomly selected 10
numbers a total of three times.