Plants grow naturally towards the strongest source of light, this is called phototropism. They do this in order to maximise their exposure to the sun and increase the amount of photosysnthesis (and therefore growth). This is a survival mechansim.
researcher will either use random assignment or matching What do random assignment and matching have in common? They are both designed to create equivalent groups of participants. Random assignment is to random selection as _____ is to _____
The table belows shows a matched pairs design for a hypothetical medical experiment, in which 1000 subjects each receive one of two treatments - a placebo or a cold vaccine. The 1000 subjects are grouped into 500 matched pairs. Each pair is matched on gender and age. For example, Pair 1 might be two women, both age 21. Pair 2 might be two men, both age 21. Pair 3 might be two women, both age 22; and so on. For this hypothetical example, the matched pairs design is an improvement over a completely randomized design. Like the completely randomized design, the matched pairs design uses randomization to control for confounding.