Tatyana is conducting an experiment where she gives participants a cup of regular or decaffeinated coffee and then asks them to complete a word-search puzzle. she wants to know if the amount of caffeine in the coffee will affect the time it takes to complete the puzzle. what is the independent variable in this study?
The independent variable is the amount of caffeine in the coffee the participants drink. The caffeine amount is being changed throughout the experiment and it is being measured, so it qualifies as an independent variable. An independent variable is changed to see how they affect the dependent variables.