The sampling method that seems to be implied here is convenience sampling, as the sample consists of volunteers. In convenience sampling, participants are selected based on their easy availability and willingness to participate. This method is often used in preliminary research to get a gross estimate of the results, without incurring the cost or time required to select a random sample. It's important to remember that the alpha level of .05 is a standard in many fields of research, indicating a 5% risk of concluding that a difference exists when there is no actual difference. The sample size of 30 for each group is a common rule of thumb for having enough power to detect an effect if one truly exists. rewrite