Three redwood trees are kept at different humidity levels inside a greenhouse for 12 weeks. One tree is left outside in normal conditions. Height of the tree is measured once a week.

What is the standardizing variable?

Question

Three redwood trees are kept at different humidity levels inside a greenhouse for 12 weeks. One tree is left outside in normal conditions. Height of the tree is measured once a week.

What is the standardizing variable?

jadedry · Answer

A standardized variable is a "constant" between the different subjects. The humidity is different, so that is out of the question. The height is not mentioned, so I don't believe this can be taken into account. I'm going to say that the type of tree (Redwood) is the standardizing variable. You can read more about it here: http://www.ehow.com/info_8718452_standardized-variable-biology.html