Biology Forums - Study Force

Which of the following are true statements related to determination of minimum sample size? (Select all that apply.)
 
  a. In inferential quantitative research, power analysis drives sample size.
  b. In pilot research, ability to address the purpose for the pilot drives sample size.
  c. In descriptive research, availability of subjects drives sample size.
  d. In both quantitative and qualitative research, available funding drives sample size.
  e. In qualitative research, theoretical saturation drives sample size.

ANS: A, B, C, E
Currently, the deciding factor in determining an adequate sample size for correlational, quasi-experimental, and experimental studies is power. Power is the capacity of the study to detect differences or relationships that actually exist in the population. Determining the sample size needed to obtain sufficient power is made by performing a power analysis. In descriptive or descriptive correlational research conducted in a natural setting, it is usual to include all available subjects.Sample size in both quantitative and qualitative research should be determined by the researcher's available funding. The number of participants in a qualitative study is adequate when saturation of information is achieved in the study area, which occurs when additional sampling provides no new information, only redundancy of previously collected data. A pilot study's sample size is very smalljust enough to address the reason the pilot was conducted. For instance, a small pilot study can be performed to measure the effect size, so that the researchers can perform an informed power analysis for the subsequent quantitative study, estimating its required sample size appropriately.