Bom dia Listeiros,

Como iniciante em analise multivariada, estou tentando trabalhar com analise multivariada (em particular Analise fatorial), para fazer isso usei a função do "factanal" do package 'stats', e também a package 'FactorMineR'. A analise fatorial busca reduzir o numero de variáveis de um banco de dados e através de seus fatores (ou variáveis latentes) construir uma nova base de dados que represente de forma mais significante a variância do banco de dados original, correto?.

Segue o resultado utilizando a 'factanal'
Call:
factanal(x = dad, factors = 15, scores = c("Bartlett"), rotation = "varimax")
Uniquenesses:
   a1    a2    a3    a4    a5    a6    a7    a8    b1    b2    b3    b4    b5    b6    c1    c2    c3    c4    d1    d2    d3    d4    d5    d6    e1    f1
0.005 0.614 0.305 0.239 0.218 0.237 0.657 0.588 0.013 0.120 0.318 0.074 0.279 0.085 0.005 0.005 0.005 0.005 0.005 0.005 0.486 0.749 0.651 0.005 0.214 0.005
   f2    f3    f4    g3    h1    h2    i1    i2    i3    i4    i5    i6    i7
0.714 0.554 0.260 0.181 0.605 0.674 0.301 0.005 0.005 0.005 0.005 0.005 0.652
Loadings:
   Factor1 Factor2 Factor3 Factor4 Factor5 Factor6 Factor7 Factor8 Factor9 Factor10 Factor11 Factor12 Factor13 Factor14 Factor15
a1  0.290  -0.328   0.521           0.251   0.461           0.106                   -0.133             0.457                   
a2                                 -0.117  -0.162           0.492           0.110                      0.271                   
a3 -0.103  -0.334                   0.251   0.107                           0.233                      0.656                   
a4  0.258  -0.223   0.161           0.145   0.729   0.116                                              0.120            -0.131 
a5                  0.838                  -0.102                          -0.105   -0.117                                     
a6         -0.192   0.811           0.125   0.111                                             0.119                            
a7         -0.138   0.483   0.129           0.201                                                               0.132          
a8         -0.151   0.546                   0.231                           0.105    0.105                                     
b1  0.886   0.387                  -0.127                                                                                      
b2  0.196   0.819  -0.170          -0.152  -0.149                           0.222                                        0.179 
b3  0.172   0.733                  -0.132  -0.203   0.135                                                                      
b4  0.136   0.889  -0.186          -0.152  -0.128                           0.125                                              
b5          0.735  -0.235          -0.191                                  -0.123                     -0.155            -0.170 
b6  0.848  -0.246                           0.290                                                                       -0.131 
c1  0.135                   0.952                                   0.241                                                      
c2  0.149                   0.454                                   0.582                                       0.632    0.119 
c3                          0.304                                   0.939                                                      
c4  0.126                   0.982                                                                                              
d1          0.247                           0.114   0.840                            0.446                                     
d2          0.125                                   0.960                            0.177                                     
d3                                                  0.121                            0.685                                     
d4                                                  0.184                            0.441                                     
d5          0.392                           0.232   0.119                                                       0.287          
d6  0.961   0.135                                  -0.163                                                                      
e1         -0.469   0.316           0.526   0.272  -0.174                                     0.116    0.127             0.193 
f1  0.961   0.205                                                                                                              
f2  0.329   0.199                          -0.348                                                                              
f3  0.387           0.402                           0.286                  -0.108    0.126            -0.110                   
f4  0.742  -0.224   0.133   0.112                  -0.186           0.107   0.122   -0.124                                     
g3  0.382  -0.200   0.353           0.342   0.558                           0.109                      0.114             0.208 
h1  0.598   0.132                                                                                                              
h2  0.188   0.222  -0.153   0.139   0.100                   0.184   0.117  -0.109                                        0.320 
i1  0.229           0.297                   0.589          -0.357                                                        0.255 
i2         -0.318   0.173           0.838   0.112           0.296           0.127   -0.133    0.102                            
i3  0.120                                                   0.974                                     -0.115                   
i4 -0.149  -0.346   0.143           0.774                  -0.437                   -0.116             0.122                   
i5          0.171                                                           0.957                      0.155                   
i6 -0.237  -0.154   0.152           0.119          -0.118                                     0.921                            
i7 -0.117  -0.195  -0.173           0.290  -0.218  -0.178                            0.105    0.116    0.188             0.196 
               Factor1 Factor2 Factor3 Factor4 Factor5 Factor6 Factor7 Factor8 Factor9 Factor10 Factor11 Factor12 Factor13 Factor14 Factor15
SS loadings      5.193   4.142   2.965   2.298   2.154   2.092   2.020   1.704   1.350    1.209    1.090    0.993    0.948    0.559    0.437
Proportion Var   0.133   0.106   0.076   0.059   0.055   0.054   0.052   0.044   0.035    0.031    0.028    0.025    0.024    0.014    0.011
Cumulative Var   0.133   0.239   0.315   0.374   0.430   0.483   0.535   0.579   0.613    0.644    0.672    0.698    0.722    0.736    0.747
Test of the hypothesis that 15 factors are sufficient.
The chi square statistic is 1330.5 on 261 degrees of freedom.
The p-value is 1.01e-142

Com isso vem os questionamentos, que são:
1) a variância acumulada foi próximo ao 75%, considerada boa na literatura sobre o tema, além do Chi-square de 1330.5 e um valor p<0,05. A questão são os graus de liberdade. O quanto isso pode afetar o modelo fatorial?
2) Eu posso utilizar o 'lm' para construir o modelo com os scores ou fica redundante, caso afirmativo como seria esta função?
3) por fim com o modelo construido, como posso avalia-lo?

Muito obrigado pela ajuda

Att

Bruce