The use of a well characterized, epidemiologically ascertained sample with detailed demographic and psychosocial assessments allowed for well-matched samples in terms of age, gender, and handedness.
For cohort and cross-sectional studies, these criteria were used: (1) representative sample of adequate size, (2) well-matched samples, (3) adjustment for confounder in analyses, (4) blinded assessment stated, and (5) dropouts reported (for prospective studies only).
The device was deployed across three regions of Bangladesh to determine if a consistent relationship between As concentrations in the dissolved and particulate phase could be identified from well-matched samples, following previous unsuccessful attempts to do so by the usual practice of separately collecting groundwater by pumping wells and collecting aquifer sediment by drilling.
This may reflect the greater statistical power afforded by relatively large, well-matched samples, and optimised acquisition, as well as the use of a voxel-based approach which permitted analysis of the entire white matter rather than selected regions within it.
To reduce the false positives due to this random noise, we used sample pooling for our discovery array, and performed the follow-up validation by analyzing a larger number of well-matched individual samples.
Another approach is to use two well-matched cord blood samples for one patient.
Obtaining well-matched normal human samples over different developmental stages is difficult, thus more detailed investigations in model organisms such as mouse are needed.
In other words, how well-matched are the control samples with the corrresponding experimental samples, and how robust are the controls?
The study quality is good, with well-matched groups and adequate sample size, although no blinding or intra-/inter-rater reliability assessment is mentioned.
In contrast, the primers designed by Scarcelli et al. (2011) specifically for monocots were exceedingly well-matched to the monocots sampled (97% in Acorus, 93% in Cymbidium, 92% in Oryza, and 88% in Canna), and a good match across all angiosperms.
Methods for cross-study integration of gene expression data have tended to focus on differential expression in well-matched control and experimental samples [ 12], because approaches based on correlation or absolute profiles [ 13] are dominated by laboratory and platform variability in cross-study analyses [ 14].
