PERMAP 11.7
(PERceptual MAPping Software)
PERMAP is a free, Windows-based (Win 95, 98, ME, NT, 2000, XP), real-time interactive program for making perceptual maps (also called product maps, strategic maps, sociograms, sociometric maps, psychometric maps, stimulus-response maps, relationship maps, concept maps, etc.). Its fundamental purpose is to uncover any "hidden structure" that might be residing in a complex data set. PERMAP takes object-to-object proximity values (similarities, dissimilarities, correlations, distances, interactions, psychological distances, dependencies, confusabilities, preferences, joint or conditional probabilities, etc.), or up to 30 object attribute values, and uses multidimensional scaling (MDS) to make a map that shows the relationships between the objects. Succinctly, it makes classical metric and nonmetric MDS analyses in one, two, three, … or eight dimensions, for one-mode two-way or two-mode two-way data, with up to 1000 objects and with missing values allowed. In addition, it can make several new types of MDS analyses involving error bounds or boundary conditions and it can show the affect of degrading the similarity information.
PERMAP has been downloaded and installed on thousands and thousands of PCs since 1995. This page is visited, on average, more than a half a dozen times per day but at the start of an academic semester the daily rate usually quadruples. PERMAP has been loaded on the servers of dozens of colleges and universities for use in classroom instruction and by numerous companies and research organizations.
PERMAP's claim-to-fame is that it lets you drag-and-drop objects in and out of the active set and it allows complete on-line control of the badness function, distance metric, attributes-to-proximities formula, attribute set composition, mapping weights, and metric or nonmetric MDS. It does this while the solution is running and the developing map is being displayed. The solution can be mirrored, rotated, translated, or zoomed. The bottom line is PERMAP gives you more real-time control over your solution than any other MDS program. It lets you get a "feel" for the solution and it lets you see, immediately, the changes that occur if you change any of your assumptions. All of this control is accomplished via a simple user interface.
PERMAP has been specifically designed to expose problems associated with local minima. If you have worked with MDS but have not discovered the real probability of the occurrence of results that are controlled by local minima then you need to experiment with PERMAP. This problem is well documented in the literature but too often it is ignored by new users. The problem is not solved by using rationalized starting points. You have to experiment with real-time analyses, using real data, to really understand it.
Example Output: To see a screen-shot of output, click here. It uses the 1954 results of Ekman, a psychologist who studied the dimensions of color vision, i.e., how people perceive radiation of different wavelengths. Traditionally, the Ekman data are analyzed using ordinal MDS, but as this output shows, ratio MDS gives essentially the same results. PERMAP can make either type of analysis, or interval MDS, by just clicking the on-screen button labeled “MDS TYPE.”
Downloading: The executable file and its auxiliary library files come as a unit. By clicking on the following link you can direct your browser to transfer the file Permap.zip to your computer. This file is less than 2 Mb in size.
The files are "zipped." That means that they are gathered together in one package, and the package is compressed using the zip algorithm. Compressed files download faster and are acceptable to the virus screening software of most Internet Service Providers. You will need an unzip program to open the package before you can run PERMAP's setup program.
Operation Manual: PERMAP's operation manual is approximately 75 pages long. It can be downloaded in pdf format. If you don't want your Adobe Acrobat reader to open it, right click on the link and choose Save Target As.
History: The original DOS version of PERMAP came out with limited distribution in 1993. During 1995 it was made available via the web. It got rave reviews from a small bunch of very enthusiastic and charming individuals. By 1998 it was clear that PERMAP needed to be entirely rewritten to make it compatible with the Windows operating system. The first Windows version became available in 2000.
Related Programs: For information on other multidimensional scaling computer programs, you might want to check out MDSX. The MDSX series is a library of stand-alone MDS programs with a common command language, operating under MS DOS. It is undergoing a major revision, first to make source, documentation and test data downloadable at a single program level, and second to produce Windows and UNIX versions of the package. The MDSX team is committed to the principle of not-for-profit academic software. Contact: Professor Tony Coxon at tony@tighcargaman.com or apm.coxon@ed.ac.uk for communication with the MDSX team.
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Legal Stuff: PERMAP is academic freeware. It is the copyrighted (1993-2008) property of Ronald B. Heady. You may use PERMAP and copy it as much as you want as long as you do not sell it or transfer it for a profit. PERMAP comes with no guarantee of any kind. Neither its author nor his employer accepts any liability of any kind. If you do not accept these restrictions, you do not have permission to download or use PERMAP.
Feedback: Suggestions for improvements are always welcome. Professor Tony Coxon and his classes have provided valuable comments that have speeded along PERMAP's evolution. Many thanks to them, and to all the others that have sent in suggestions for improvement or words of encouragement.
Professor Ronald B. Heady
Department of Business Systems Analysis and Technology
B.I. Moody College of Business Administration
University of Louisiana at Lafayette
PO Box 43930
email: Ron Heady