DAY 5 GROUP I

PERMAP (perceptual mapping)

PERMAP is a multidimensional scaling (MDS) computer program, use to uncover hidden structure that might be residing in a complex data set. MDS is easier to understand and its results are easier to interpret.

It offers both metric (ratio and interval) and nonmetric (ordinal, ratio + bounds, interval + bounds) MDS techniques. It solves problems in 1, 2, 3, or 4 dimensions and allows boundary conditions to be imposed on the solution.

Perceptual maps are sometimes called product maps, sociograms, sociometric maps, psychometric maps, stimulus-response diagrams, relationship maps, concept maps, etc. A perceptual map is a piece of paper, or any plane, with symbols on it that convey information about perceived relationships between the objects represented by the symbols.

The proximity information used in the form of similarities or of dissimilarities, just by replacing the keyword DISSIMILARITYLIST with SIMILARITYLIST and we have be sure that the diagonal values are all equal and are not exceeded by any other similarity value.

Permap can decode values in ASCII format only eg. Notepad.

Some Code used to program PERMAP ARE As follows

NOBJECTS=6 Gives the number of objects in the analysis.

NATTRIBUTES=3 Gives the number of attribute values for each object.

ATTRIBUTELIST Announces that attribute values follow.

 1, 1, 2                Any range can be used for the data.

 1, 2, 2                The data can be separated with space(s), a comma, or both.  

 3, 3, 2                ATTRIBUTELIST is all one word and capitalization is optional

3, 4, 0                 All data entries must be numbers.

 3, NA, 0             Missing entries are shown by "NA" or "na."

1, 6, NA              It is acceptable to name the objects.

EG.

Keyword Purpose Example Use Comment

NOBJECTS            Set number of objects

NATTRIBUTES   Set number of attributes

TITLE                     Set a title line to be shown on output

MESSAGE             Set a message to be shown on output

SUBTITLE             Set a subtitle line to be shown on output

SUBMESSAGE     Set a submessage to be shown on output

DISSIMILARITYLIST Announce that dissimilarity data follow

 SIMILARITYLIST       Announce that similarity data follow

ATTRIBUTELIST         Announce that attribute data follow

LOCATIONLIST           Announce that initial positions follow

WEIGHTLIST                Announce that weight data follow NA A missing dissimilarity value

PROCEDURE TO OPEN DATA FILE IN PERMAP

CLICK ON PERMAP.exe icon

 GOTO FILE -àLOAD DATA FROM DATA INPUT FILE/ F2-----àSELECT DATA FILE .

select file which i to be analyse

SELECT--à START

Automatic Controls

The Auto Repeat and Auto Stop check boxes control whether or not a run automatically stops, and then possibly automatically restarts, after a certain convergence limit (as set using the Convergence menu) is reached. These controls facilitate finding numerous solutions, each starting from a new set of random positions, to be sure that a global minimum has been found. The best-found value is displayed in brackets just below the current objective function value. Next to the best-found value is the number of times that the best-found value has been found, followed by the number of times the problem has been solved using the current set of parameters.

OUTPUT

Result can be adjusted in different views using mirror, jiggle and field button

Field Movements (Mirror, Rotate, Move, Zoom)

Occasionally you will want to control the final orientation of a map in order to make a simple comparison to previous results, or you might want to expand a map to inspect a small, congested, area. These needs can be satisfied by mirroring, rotating, moving, or zooming in. These operations are known as "field movements" because the chosen operation applies to the whole field of objects. The field movement controls are activated by clicking the Field button or right clicking the mouse on an open area. first select the desired type and then use the mouse to control the execution of the movement. If Mirror is chosen, then clicking near an axis will cause the map to be mirrored about that axis. If Rotate is chosen, then dragging the mouse about the center of the map will cause the object set to rotate about the center. If Move is chosen, then dragging the mouse in any direction will cause the object set to move in that direction. Finally, if Zoom is chosen, then dragging the mouse away from the center of the map will cause the object set to expand, and vice versa. The results of all of these movements persist after the field controls are closed. Remember that if a MDS solution is mirrored it is a valid solution. This is true for any type of MDS, badness measure, distance measure, and weighting scheme. The validity of a solution is similarly invariant to all rotations, but only if the Euclidean distance measure is used.

by

Sushilkumar Balvir
Reference: http://belkcollegeofbusiness.uncc.edu/jaredhansen/Teaching/MBA%20Marketing%20Research/PermapManual.pdf