Multiple
Correspondence Analysis (MCA): Table Specifications Startup Panel - Multiple
Correspondence Analysis (MCA) Tab
Select the Multiple Correspondence
Analysis (MCA) tab of the Multiple Correspondence Analysis (MCA): Table
Specifications Startup Panel to access the options described
here. Use these options to specify the input table for the multiple
correspondence analysis.
Input.
Three data file format options are available in the Input group box: Raw data (requires tabulation), Frequencies with grouping variables, and
Frequencies w/out grouping vars.
Depending on the Input method selected (see above), one or more of the
following option buttons will be available.
Variables
(Factors in Burt Table). Click
the Variables (Factors in Burt Table)
button to display the standard variable
selection dialog box, in which you select the variables that will
be used in the analysis. The Burt
table (see also Multiple
Correspondence Analysis (MCA) - Introductory Overview will be computed
for the categories of the selected variables.
Codes
for grouping variables. Click the Codes
for grouping variables button to display the Select
Codes for Coding Variables dialog. Use this dialog to enter
the codes
(numbers or text labels) that define the categories for the selected variables.
Note that the Codes for grouping variables
button is only available after the
Variables (e.g., factors in the
Burt table) are selected.
Supplementary
columns (variables). Click the
Supplementary
columns (variables) button to
display the standard variable
selection dialog, in which you designate the variables to be analyzed
as supplementary
columns (variables). Note that unlike in simple correspondence analysis,
where supplementary columns and rows can be added from the Correspondence
Analysis Results dialog box -
Supplementary points tab,
in multiple correspondence analysis it is required that the supplementary
columns also define a valid Burt
table. Therefore, in this case, specify all variables for the analysis
via the Variables
(Factors in Burt Table) button,
and then select the subset of those variables that are to be treated as
supplementary columns via the Supplementary
columns (variables) button.
The variables selected as supplementary columns will not be used for the
computation of eigenvalues
and eigenvectors (see Computational Details), but coordinate
values will be computed for those columns and reported in the spreadsheet
and plots of coordinates.
Variable
with frequencies/counts. Click the Variable
with frequencies/counts button to display the standard variable
selection dialog, in which you select the appropriate variable that
will be used in the analysis (i.e., the variable containing the measure
of correspondence, similarity, confusion, association, etc.). Only positive
values or zero are allowed in this variable (e.g., STATISTICA
does not permit negative frequencies). Note that the Variable with frequencies/counts button
is only available when the Frequencies
with grouping variables option button is selected via the
Input group box.
Variables
with frequencies. Click the Variables
with frequencies button to display the standard variable
selection dialog, in which you select the appropriate variables that
will be used in the analysis. The data in the selected variables (and
cases) are expected to define a valid Burt table (see the Introductory
Overview - MCA). Note that the Variables
with frequencies button is only available when the Frequencies w/out grouping vars
option is selected via the Input
group box.
Specify
structure of table. Click the Specify
structure of table button to display the Specify the dimensions of the
table dialog, in which you enter the factor names (e.g., survival,
age, location) and the number of levels for each factor (e.g., 2, 3, and
3). When processing the data, STATISTICA
will automatically check whether the respective data specify a valid Burt
table. Note that the Specify structure
of table button is only available after Variables
have been selected.
For examples and more detailed information on specifying tables for
Multiple Correspondence Analysis,
see Raw Data
(Requires Tabulation), Frequencies
with Grouping Variables, and Frequencies
without Grouping Variables. See also, Multiple
Correspondence Analysis.