Computational Diagnostics Group compdiag MPI for Molecular Genetics

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The methods of the R/Bioconductor compliant package OrderedList provide a comparison of comparisons. Say, we compare two gene expression studies. Both are comparisons of two states. Preferably, one state relates to a good outcome or prognosis and the other one relates to a bad outcome. For each study separately, we might conduct a two-sample test per gene to discover differentially expressed genes. Although each single study might not necessarily reveal significant changes, we observe considerable overlap in the top-ranking genes. Hence, we wish to compare the results of the two comparisons.

We assign a similarity score to a comparison of two ranked (ordered) gene lists. The similarity score is based on the number of overlapping genes in the top ranks. For each rank, the size of overlap is computed. The final score is in principle a weighted sum of these values, with more weight put on the top ranks.

OrderedList example Figure: Displayed are the numbers of overlapping genes in the comparison of two gene lists. The overlap size is drawn as a step function over the respective ranks. Top ranks correspond to up-regulated and bottom ranks to down-regulated genes. In addition, the expected overlap and 95% confidence intervals derived from a hypergeometric distribution are shown.


  • Scheid S, Lottaz C, Yang X, and Spang R (2006):
    Similarities of Ordered Gene Lists - User's Guide to the Bioconductor Package OrderedList
    CompDiag Technical Report Nr. 2006/01 Mar. 2006
    [ pdf ]


Download the tared and gzipped source file as submitted to Bioconductor. To run the package, you need R and the Bioconductor packages Biobase and twilight. Package OrderedList includes a user's manual which can be downloaded separately from above.

Direct installation from the CompDiag R-repository

Start the R version where you want to install OrderedList. Use the following commands on the R prompt to install OrderedList directly from our repository:

    z <- getReposEntry("")
    install.packages2("OrderedList", z)

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