Quantile Regression

Appendix CApplications of Factor Analysis

In Chapter 10, we presented QRs of a baby latent variable (BLV) on alternative IVs, including a mother latent variable (MLV), based on the data in BBW.wf1. This appendix presents the specific factor analyses to generate the BLV and MLV.

C.1 Generating the BLV

In this section, we will develop the BLV, using factor analysis, with the steps that follow:

1. With the data on‐screen, we can obtain the dialog on the left side of Figure C.1 by selecting Object/New Objects/Factor. Then we can insert the three variables, BBW, FUNDUS, and MUAC.
2. Clicking the Estimation button produces the options on the right side of Figure C.1. If we select the Principal factors method, use 1 as the number of factors, and click OK, we obtain the output in Figure C.2.
3. We then can select View/Eigenvalues and click OK to see whether the single factor is acceptable, in the statistical sense, with an eigenvalue > 1. In this case, the output shows that a single latent variable BLV can be developed based on the three variables, BBW, FUNDUS, and MUAC.
4. After clicking Proc/Name Factors, we can insert the name BLV and click OK.
5. Finally, by selecting Proc/Make Scores and clicking OK, we make BLV directly available in the data file as a new additional variable.
6. With the output in Figure C.3 on‐screen, clicking View obtains additional statistical results, such as the Eigenvalues Summary and Kaiser's Measure of Sampling Adequacy, as presented in Figures C.3 and C.4.

C.2 Generating ...