Answer:
This sampling method is called cluster sampling.
Explanation:
In cluster sampling, the researcher will first divide the population into separate groups. The researcher in the passage focused on sixth graders of a certain state as his subjects. The next step is to select a simple random sample of clusters from that population. In this case, the researcher randomly selected 5% of the districts in the state, and administered the achievement test to their sixth graders. Therefore, we can safely say he used cluster sampling.
<span>Researchers fail to control variables that then damage the overall integrity of an experiment. The conclusions can be wildly inaccurate as a result. The results may show a negative correlation between variables that invalidate the total effort. The researchers assume variables but do not account for a variable that influences the statistical outcome of the experiment.</span>
