Researchers need to understand the variability in their data and what is creating it. Researchers view measurement error variability as "bad" and attempt to minimize it. Researchers also recognize that individual differences variability will always create variation in their data. In contrast, researchers may want to cerate variability by assigning different kinds of treatments. A researcher wants to know if physically touching prematurely born infants could increase their growth. This was done using two groups of prematurely born infants (one group touched with skin-to-skin contact 6 hours a day, vs one group touched by someone wearing gloves).
The fact that researchers gave some infants 6 hours of skin-to-skin touch a day and some other infants no skin-to-skin touch contributes to the amount of________________________ in this study.
Group of answer choices
measurement error variability
individual differences variability
treatment differences variability