PERMAP is a free, Windows-based (Win 95, 98, ME, NT, 2000, XP, Vista, Win7), real-time interactive program for making two-dimensional perceptual maps (also called product maps, strategic maps, sociograms, sociometric maps, psychometric maps, stimulus-response maps, relationship maps, concept maps, etc.) of objects which have multidimensional relationships. It differs in this respect from NewMDSX in which dimensions are plotted separately and the viewpoint can be varied. 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 (also called similarities, dissimilarities, correlations, distances, interactions, psychological distances, dependencies, confusabilities, preferences, joint or conditional probabilities, etc.), or up to 30 object attribute values which can be used to calculate one of the forgoing types of promities, and uses multidimensional scaling (MDS) to make a map that shows the relationships between the objects. Succinctly, PERMAP 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. Ignoring jargon, PERMAP makes all the common types of MDS analyses. 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 proximity (similarity) information.
PERMAP has been downloaded and installed on thousands of PCs since 1995. This page is visited about 15 to 20 times per day but at the start of an academic semester the daily rate usually doubles. PERMAP has been loaded on the servers of dozens of universities, companies and research organizations.
PERMAP's main claim-to-fame is that it lets you drag-and-drop objects in and out of the active set while the map is evolving and being displayed. It also 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, again, 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 that 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.
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 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. See the PERMAP operation manual for more information on this important point.
Downloading: The executable file and some example files come as an installable unit for use in conjunction with the NewMDSX package. By clicking on the following link you can direct your browser to install the files to your computer.
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, be sure to check out the entire NewMDSX web site. Contact: firstname.lastname@example.org for communication with the NewMDSX team.
Legal Stuff: PERMAP is academic freeware. It is the copyrighted (1993-2011) 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 is offered as is. It comes with no guarantee of any kind. Its author accepts no liability associated with its use. If you do not accept these restrictions then 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.