Question

phoebe is taking samples from a lake to determine how the populations of aquatic life change during the summer. each week, for a month, she takes samples from different areas of the lake. over the course of a month, she finds the marine life listed in the chart below. what should phoebe change about her methodology to better address her question?

	week 1 location 1	week 2 location 2	week 3 location 3	week 4 location 4
crawfish	8	15	20	22
fish	3	11	13	12
other	5	2	8	4

• provide details about other creatures in the \other\ category.
• take samples from the same location each time.
• collect samples from a different habitat.
• use a more sophisticated net to collect smaller creatures.

Explanation:

To accurately determine how the populations of aquatic life change during the summer, samples should be taken from the same location over time to control for location - specific variables. Changing locations each week confounds the results and makes it hard to attribute changes to the passage of time.

Answer:

Take samples from the same location each time.