Galo Example

Topics Addressed

1. Nonlinear Multivariate Analysis Techniques
2. Education

We use the Galo dataset to illustrate some of the nonlinear multivariate techniques.

A description of the variables follows:

1. Gender
   1. Boys
   2. Girls
2. IQ - values between 60 and 144
3. Teacher's advice
   1. No further education
   2. Extended primary education
   3. Manual, including housekeeping
   4. Agricultural
   5. General
   6. Secondary school for girls
   7. Pre-University
4. Father's profession
   1. Unskilled labour
   2. Schooled labour
   3. Lower white collar
   4. Shopkeepers
   5. Middle white collar
   6. Professional, Managers
5. School - numbers 1 - 37

A summary of the data is given in Table 1.

Since the IQ variable is continuous we recoded it into the five categories given in Table 1. The first analysis of the Galo data uses the HOMALS (Homogeneity Analysis) technique (see Gifi (1990) chapter 3). The second analysis illustrates the use of the PRINCALS (Nonlinear Principal Component Analysis) technique (see Gifi (1990) chapter 4).