| metaanalyse.Cliffd {reproducer} | R Documentation |
metaanalyse.Cliffd
Description
This function provides a simple meta-analysis of experiments using Cliff's d as an effect size. It returns the 100*(1-alpha/2)
Usage
metaanalyse.Cliffd(
Cliffd,
Cliffdvar,
df = 0,
alternative = "two.sided",
alpha = 0.05
)
Arguments
Cliffd |
A vector of one or more numerical values, identifying the effect sizes to be meta-analysed |
Cliffdvar |
A vector of the estimates variance of each of the effect sizes |
df |
The total degrees of freedom for the set of effect sizes. If df>0, the pvalues and significance test use the t-distribution probability values. If df=0 (default) the pvalues and significance test use the normal distribution probability values. The confidence intervals are always based on the normal probability values, as recommended by Cliff. |
alternative |
Specifies the type of significance test and can take the values "two.sided" (default), "less" or "greater". |
alpha |
The significance level used to control the significance tests and calculation of confidence limits (default 0.05). |
Value
Estimate The overall estimate of Cliff's d obtained from the set of experiments
UpperCI The upper 100*(1-alpha/2)
LowerCI The lower 100*(1-alpha/2)
The variance of the Estimate
tvalue The value of the t-statistic
df The supplied degrees of freedom or NA if the input parameter df was set to zero
AltHyp Defines the alternative hypothesis used for significance testing and depends on the value of the input parameter alternative. It takes the values "Not=0", ">0", or "<0"
NullHyp Defines the null hypothesis and depends on the value of the input parameter alternative. It takes the values "~0", "<0", or ">0"
pvalue The p-value of the t-test if the parameter df>0, or the normal probability value if d=0
RejectNullHyp "Yes" or "No" depending on whether or not the null hypothesis should be rejected at the alpha/2 level for two-sided tests and alpha level for one-sided tests
The Q homogeneity statistic
The I-squared estimate of the extent of heterogeneity
ProbQHomogeneous. The probability that the set of Cliff's d values come from a set of homogeneous experiments.
Author(s)
Barbara Kitchenham and Lech Madeyski
Examples
Cliffd=c(0.84,0.2,-0.04,0.44,0.76)
CliffdvarInvalid=c(0.04,0.18,0.21,0.15)
Cliffdvar=c(0.04,0.18,0.21,0.15,0.06)
CliffdvarInvalid=c(0.04,0.18,0.21,0.15)
df=45
as.data.frame(metaanalyse.Cliffd(Cliffd=Cliffd,Cliffdvar=Cliffdvar,df=df,alternative="greater",
alpha=0.05))
# Estimate UpperCI LowerCI Variance tvalue df AltHyp NullHyp pvalue
#1 0.44 0.6601381 0.1502568 0.0256 2.75 45 >0 <=0 0.004275955
# RejectNullHyp Q I.square ProbQHomogeneous
#1 Yes 21.5 81.39535 0.0002519835
as.data.frame(metaanalyse.Cliffd(Cliffd=Cliffd,Cliffdvar=Cliffdvar,df=df,alternative="less",
alpha=0.05))
# Estimate UpperCI LowerCI Variance tvalue df AltHyp NullHyp pvalue RejectNullHyp
#1 0.44 0.6601381 0.1502568 0.0256 2.75 45 <0 >=0 0.995724 No
# Q I.square ProbQHomogeneous
#1 21.5 81.39535 0.0002519835
as.data.frame(metaanalyse.Cliffd(Cliffd=Cliffd,Cliffdvar=Cliffdvar,df=df,alternative="two.sided",
alpha=0.05))
# Estimate UpperCI LowerCI Variance tvalue df AltHyp NullHyp pvalue
#1 0.44 0.692073 0.09227496 0.0256 2.75 45 Not=0 ~0 0.008551911
# RejectNullHyp Q I.square ProbQHomogeneous
#1 Yes 21.5 81.39535 0.0002519835
as.data.frame(metaanalyse.Cliffd(Cliffd=Cliffd,Cliffdvar=Cliffdvar,df=df,alpha=0.05))
# Estimate UpperCI LowerCI Variance tvalue df AltHyp NullHyp pvalue
#1 0.44 0.692073 0.09227496 0.0256 2.75 45 Not=0 ~0 0.008551911
# RejectNullHyp Q I.square ProbQHomogeneous
#1 Yes 21.5 81.39535 0.0002519835
metaanalyse.Cliffd(Cliffd=Cliffd,Cliffdvar=Cliffdvar,df=0,alternative="two.sided",alpha=0.05)
#Error in testfunctionParameterChecks(alternative = alternative, alpha = alpha, :
# Invalid alternative parameter, choose one of two.sided, greater or less
# metaanalyse.Cliffd(Cliffd=Cliffd,Cliffdvar=CliffdvarInvalid,df=df,alternative="greater",
# alpha=0.05)
#Error in metaanalyse.Cliffd(Cliffd = Cliffd, Cliffdvar = CliffdvarInvalid, :
# Length of Cliffdvar parameter must equal the length of the Cliffd parameter