What is the independent variable in this experiment?

There are two people growing avocado plants. They record the height of the plant everyday for 16 days. The dependent variable is the height, but what is the independent variable? Would it be who is growing the plant, or the time?



Thank you!What is the independent variable in this experiment?
Assuming "Ceteris paribus" (namely soil type, envoirnment like temprature sunlight , equal capbaility of both individuals) you can have time spend on tending the plant as dependent variable.



Height of Plant = a x T + C



T = time spent

C= error term

a = co-efficent of T

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