Galbraith plot
Encyclopedia
In statistics
, a Galbraith plot (also known as Galbraith's radial plot or just radial plot), is one way of displaying several estimates of the same quantity that have different standard error
s.
It can be used to examine heterogeneity in a meta-analysis
, as an alternative or supplement to a forest plot
.
A Galbraith plot is produced by first calculating the standardized estimates or z-statistics by dividing each estimate by its standard error
(SE). The Galbraith plot is then a scatter plot of each z-statistic (vertical axis) against 1/SE (horizontal axis). Larger studies (with smaller SE and larger 1/SE) will be observed to aggregate away from the origin.
Statistics
Statistics is the study of the collection, organization, analysis, and interpretation of data. It deals with all aspects of this, including the planning of data collection in terms of the design of surveys and experiments....
, a Galbraith plot (also known as Galbraith's radial plot or just radial plot), is one way of displaying several estimates of the same quantity that have different standard error
Standard error
Standard error can refer to:* Standard error , the estimated standard deviation or error of a series of measurements* Standard error stream, one of the standard streams in Unix-like operating systems...
s.
It can be used to examine heterogeneity in a meta-analysis
Meta-analysis
In statistics, a meta-analysis combines the results of several studies that address a set of related research hypotheses. In its simplest form, this is normally by identification of a common measure of effect size, for which a weighted average might be the output of a meta-analyses. Here the...
, as an alternative or supplement to a forest plot
Forest plot
A forest plot is a graphical display designed to illustrate the relative strength of treatment effects in multiple quantitative scientific studies addressing the same question. It was developed for use in medical research as a means of graphically representing a meta-analysis of the results of...
.
A Galbraith plot is produced by first calculating the standardized estimates or z-statistics by dividing each estimate by its standard error
Standard error
Standard error can refer to:* Standard error , the estimated standard deviation or error of a series of measurements* Standard error stream, one of the standard streams in Unix-like operating systems...
(SE). The Galbraith plot is then a scatter plot of each z-statistic (vertical axis) against 1/SE (horizontal axis). Larger studies (with smaller SE and larger 1/SE) will be observed to aggregate away from the origin.
External links
- MIX 2.0 Software to perform meta-analysis and create Galbraith plots in Excel.