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: enquiries@newmdsx.com
for
communication with the NewMDSX team.
A
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.