ARTICLE IN PRESS Omega ( ) – www.elsevier.com/locate/omega Presenting DEA graphically  Nicole Adler ∗ , Adi Raveh School of Business Administration, Hebrew University of Jerusalem, Israel Received 21 September 2005; accepted 22 February 2006 Abstract This paper introduces a methodology that permits presentation of the results of data envelopment analysis (DEA) graphically. A specialized form of multi-dimensional scaling, Co-Plot, enables presentation of the DEA results in a two-dimensional space, hence in a clear, understandable manner.When plotting ratios rather than original data, DEA efficient units can be visualized clearly, as well as their connections to specific variables and/or ratios. Furthermore, Co-Plot can be used in an exploratory data analysis to identify outliers, whose data require additional scrutiny, and potentially inconsequential variables that could be aggregated or removed from the analysis with little effect on the subsequent DEA results. The Co-Plot diagram of ratios presents super-efficient observations on an outer ring or sector of the plot and all reasonably efficient units on a slightly inner ring/sector, surrounding the remaining inefficient decision-making units. First, the well-known 35 Chinese Cities dataset is provided as an illustration. Second, a simulation study tests the applicability of Co-Plot to present the results of DEA.  2006 Elsevier Ltd. All rights reserved. Keywords: Data envelopment analysis; Multi-dimensional scaling; Efficiency; Co-Plot 1. Introduction The purpose of this paper is to suggest a methodology for presenting data envelopment analysis (DEA) graphically. The graphical display method, Co-Plot, is a variant of multi-dimensional scaling [1,2]. Co-Plot locates each decision- making unit (DMU) in a two-dimensional space in which the location of each observation is determined by all variables simultaneously. The graphical display technique exhibits DMUs as points and variables as arrows, relative to the same axis and origin or center-of-gravity. Observations are mapped such that similar DMUs are closely located on the plot, signifying that they belong to a group possessing comparable characteristics and behavior. The Co-Plot method has been applied to a study of socioeconomic differences among cities [3], national versus corporate cultural fit in mergers and acquisitions [4], computers [5] and the Greek banking system [1]. Several papers have been published in the literature discussing the use of multivariate statistical approaches within the DEA context, mostly for the purposes of ranking, see for example Adler et al. [6].  This manuscript was proccessed by Area Editor Prof. B. Lev. ∗ Corresponding author. Tel.: +972 2 5883449. E-mail addresses: msnic@huji.ac.il (N. Adler), msraveh@huji.ac.il (A. Raveh). 0305-0483/$ - see front matter  2006 Elsevier Ltd. All rights reserved. doi:10.1016/j.omega.2006.02.006