Multiple Correspondence Analysis Results - Advanced Tab

Select the Advanced tab of the Multiple Correspondence Analysis Results dialog box to access the options described here.

Row & column coordinates. Click the Row & column coordinates button to display a spreadsheet with the coordinates for the column points, as well as various additional statistics that are useful for evaluating the adequacy of the number of dimensions in the current solution. Also, if you have specified supplementary column points, then the coordinates for those points, as well as related statistics, will also be included in the spreadsheet.

The results of a multiple correspondence analysis are identical to a simple correspondence analysis of the indicator or design matrix, whose inner product is the current Burt table (see Multiple Correspondence Analysis (MCA) - Introductory Overview). Therefore, the interpretation of the typical statistics reported as the result of a multiple correspondence analysis are analogous to those of the simple correspondence analysis (of an indicator matrix). For more details about the statistics reported in these spreadsheets, see Column Coordinates in Multiple Correspondence Analysis.

Print/report Summary Box. Click the Print/report Summary Box button to send the information shown in the Summary box to a report and to display spreadsheets of the analysis results. If the current Output Manager settings do not specify output to a report when you click the Print/report summary of results button, a dialog will be displayed that gives you the option to modify the Output Manager. Click the Yes button to display the Analysis/Graph Output Manager dialog box, in which you can select an Output Report Window option.

Eigenvalues. Click the Eigenvalues button to display a spreadsheet with the generalized singular values, eigenvalues, and related statistics. Note that the dimensions are "extracted" so as to maximize the distances between the column points, and successive dimensions (which are independent of or orthogonal to each other) will "explain" less and less of the overall inertia (refer to Computational Details for additional information).

Plot. Click the Plot button to display a line plot of the eigenvalues for the successive dimensions.

Unstandardized matrices. Click the Unstandardized matrices button to display a spreadsheet with the relative frequencies (i.e., the values in the input table, divided by the sum of all values), and the matrix of generalized singular vectors (see also Computational Details; because the Burt table is symmetrical, the left- and right-side singular vectors are the same). This option is useful if you want to access these matrices via a STATISTICA Visual Basic program, for example, in order to implement a non-standard method of standardizing the column coordinates. See also the analogous option in the Correspondence Analysis Results dialog box topic for additional computational details.

Plots of coordinates. The options in the Plots of coordinates group box allow you to plot the column points, along with supplementary points (if any were specified) in 1D plots, 2D plots, or 3D plots. Note that you can use the brushing options to eliminate individual points from the plots (e.g., to leave only points that are clearly spread out along the axes). Also, the orientation of axes is arbitrary, and can, for example, be rotated by 180°. Note that you can quickly achieve this "reversal of scales": right-click on the graph and select Graph Options from the resulting menu to display the Graph Options dialog box; select the Axis Scaling tab, and select the Reverse scaling check box.

Row/Column 1D, 2D, 3D. If you click any of these graph buttons, the respective plots will be produced for all dimensions, pairs of dimensions, or triplets of dimensions currently selected via the options in the Number of dimensions group box (accessible on the Quick tab and Options tab). By default, the points will be labeled with the full column names from the table.

Plot selected dimensions only. Select the Plot selected dimensions only check box to plot the points for selected dimensions, pairs of dimensions, or triplets of dimensions only. When this box has been selected, click any of the Column 1D, 2D, or 3D graph buttons to display the Select the Dimensions to Plot dialog box, in which you can select the list of dimensions for which to produce the respective plots.

Truncate labels to chars. Select the Truncate labels to chars check box and enter a value in the corresponding field to display only the specified number of characters of the row and column point names in the graphs. By default the points in the plots will be labeled with the full names for the row and column points. For large tables with many points, the plots may be more readable when you abbreviate the row and column point names.

Use identical X/Y/(Z) scales. Select the Use identical X/Y/(Z) scales check box to force all axes in 2D and 3D plots to use identical scaling (minima and maxima) and thus achieve compatibility of scales between dimensions (i.e., axes in the plot). As described in the Introductory Overview, by default (depending on the selected method of Standardization of coordinates, accessed via the Options tab) the distances between the points in the plots are actually Chi-square distances.