Factor | Brief definition or question of interest | Key references* |
---|---|---|
Sample size | Estimation of the number of arrays required in order to identify significantly, differentially expressed genes. | [15–26] |
Statistical power | Ability of a study to detect a true difference between genes, biological category or condition | [2,24,27–28] |
Normalisation | Does the paper report normalisation of data? (yes or no) | [29–32] |
Normalisation method | Does the paper describe how sources of variation were removed or data standardisation method, e.g. total intensity normalisation, normalisation using regression techniques, normalisation using ratio statistics etc. | [29–32] |
Test directionality | Explicit statement of directionality of the statistical test applied, i.e. one-sided or two-sided test | [33–35] |
Hypothesis and alternative | Explicit statement of null (H0) or alternative hypothesis (H1) | [36–39] |
Missing values | Report of missing values, report of estimation of missing values or description of method for estimating missing values. | [40–42] |
Software | Which software, programs or tools were used for statistical analysis? | [43–44] |
Analysis technique | Which statistical approaches were used for gene expression data analysis? | [1,45–47] |
Homogeneity of variances | Does the paper report the equality of variances assumption for the application of ANOVA and t-test? | [48–49] |