assumed stable character

statistical data distribution

constant ratio tendency

expression levels of particular genes

sum of signal data

smallest differences in log(data)

smallest differences in arsinh(data)

Can the assumption be verified?

yes [22, 26] Figs. 1,2

no

yes^{1}

no

no

no

units for expression level

zscore

ratios to a reference

ratios to the stable genes

fraction (ppm)

ratios to a reference

statistical differences to a reference

data transformation for the adjustment

subtraction of a constant

nonlinear

no

no

linear on logarithms

linear

numbers of data sets normalized in a calculation

1

2

1

1

all the sets to be compared

2

Can it compare multiple data sets without reference RNA?

yes

no

yes

yes

yes

no

amount of calculation

medium

medium

least

least

vast

largemedium

reproducibility

yes Figs. 3,8

no Fig. 7

nt^{3}

no [7]

no^{2}

no Fig. 6cd

Is the ratio tendency independent of signal intensity?

yes Figs. 5,8

yes Fig. 6b

nt^{3}

no Fig. 6a

no^{2}

yes Fig. 6cd

Is the ratio variance independent of signal intensity?

yes Figs. 5,8

no Fig. 6b[7]

nt^{3}

no Fig. 6a

no^{2}

yes Fig. 6cd

Can it find the level of additive noise in the data?

yes

no

no

no

no

no
