A biologist is studying the possible role of earthworms on the fertility of farm soils. As part of this research, the number of earthworms per acre of farmland is being estimated. During the first phase of this study, a total of 5 one-meter square samples were taken per acre. The number of earthworms in each of the five samples was carefully counted and the results used to estimate the total number of earthworms per acre. How can this estimate of the number of earthworms per acre be improved?

Taking more samples from different parts of an acre.

Explanation:

Validity and accuracy of the data is crucial for any serious research. In this particular case, the most accurate data would be obtained if earthworms would be counted on the whole acre. Of course, this would consume lot of time, people, money etc. That's why methods for estimation are used. Estimation best works with large number of samples. Since one acre equals over 4000 square meters, taking only five samples from such a big area is simply not enough for obtaining valid data.

One of the possible ways to improve estimation is to take more samples per acre while avoiding taking adjacent samples because it could be possible that number of earthworms in one part of an acre is increased (or decreased) for any reason, which would lead us to wrong conclusion.