Lack of a priori defined sample size calculations leading to insufficient sample sizes and ultimately insufficient statistical power [73]; studies with an insufficient sample size can thus lose their ethical justification [74].
Following a basic premise of qualitative research, we avoided establishing an a priori defined sample size for the focus group discussions.
Therefore, the variance of this cluster sample with a defined sample size may be larger than that of a simple random sample, and hence the estimates are less precise.
Although the sample is a convenience sample, Miettinen [ 20] stated that for associations to be generalized to other populations, three key criteria including selection (inclusion/exclusion criteria for both offspring and controls are explicitly defined), sample size and adequate distribution of study factors need to be met, all of which are met by this study.
To calculate cell numbers, defined sample sizes were acquired and the number of cells normalized as cells/dl of the initial urine sample.
Unfortunately, non-parametric tests do not have well defined sample effect sizes and so it is not possible to use them as an absolute point of comparison that is independent of sample size.
Using random extractions of trees, iterative mapping, and a stratified sampling strategy based on an arbitrary selection of trees, we investigate subsets of the full tree-ring data set to define optimal sample size and sampling design for the development of frequency maps of rockfall activity.
To define the sample size, a Simon's two-stage design was utilised (Simon, 1989), setting α and β errors as 0.05 and 0.20, and defining as minimum activity of interest (p0) a TRG1 2 rate=30%.
We see that for both 15 and 50 features and for moderate to high sample sizes (where we define moderate sample size as for and for, VB outperforms FW and performs similar to BW. For small sample sizes, FW and BW outperform VB. Figure 8 Mean classification error versus log sample size; (a) is for dimensionality, and (b) is for.
In 5 papers, the method used to define the sample size was not explicitly stated and only references were provided.
