As the p-value for gene selection becomes more stringent, the correlation increases (data not shown).
Nevertheless, as the p value threshold of the A-C test defining differential expression became more stringent, the correlation became more evident, although the degree to which this occurred varied with tissue type (Fig. 2).
The three-state SSE assignments for each method are compared to DSSP using several commonly levied metrics including the percentage similarity, the more stringent Matthews correlation coefficient (MCC) (Matthews, 1975) and the MCC squared.
Weighted correlations are used as they are more stringent for detecting true correlations, as they will favor higher correlations over lower correlations (which can often occur due to chance).
Evidence for kin discrimination often relies on correlational evidence without demonstration of exact mechanisms, yet skeptics of reciprocity increasingly require far more stringent evidence than mere correlation or even contingency.,,, Vampire bats demonstrate symmetrical exchanges of help, but it has yet to be demonstrated that vampire bats use conditional enforcement to prevent cheating.
Given the short time since the start of the Canarian radiation, we are probably witnessing the initial stages of a process of phenotype-environment driven differentiation, although to demonstrate ecological differentiation and adaptive radiation more stringent tests than simple correlations are needed (see [ 90]).
Briefly, Gemma uses a threshold of 0.5% on the correlation between expression profiles of genes to determine coexpression, or a p-value from the Fisher transformed correlations, whichever is more stringent [34].
A more stringent evaluation was to find out the correlation between probesets that correspond to "control RNAs" that are added in each microarray assay in the hybridization process.
Furthermore, even if there was strong correlation between visits of patients, ordinary linear regression would underestimate the correlation because it assumes that the visits are independent; therefore, the correlations of ordinary linear regressions are more stringent than those of GEE [ 64].
