> retrain.mod1 <- aov(achieve ~ trt)
> anova(retrain.mod1)
Analysis of Variance Table

Response: achieve
          Df Sum Sq Mean Sq F value    Pr(>F)    
trt        8    562   70.25  17.562 0.0001238 ***
Residuals  9     36    4.00                      
---
Signif. codes:  0 ‘***’ 0.001 ‘**’ 0.01 ‘*’ 0.05 ‘.’ 0.1 ‘ ’ 1 
> 
> retrain.mod2 <- aov(achieve ~ iq + age + method)
> anova(retrain.mod2)
Analysis of Variance Table

Response: achieve
          Df Sum Sq Mean Sq F value    Pr(>F)    
iq         2 364.33 182.167 38.2898 1.108e-05 ***
age        2  34.33  17.167  3.6083 0.0623871 .  
method     2 147.00  73.500 15.4490 0.0006391 ***
Residuals 11  52.33   4.758                      
---
Signif. codes:  0 ‘***’ 0.001 ‘**’ 0.01 ‘*’ 0.05 ‘.’ 0.1 ‘ ’ 1 
> 
> anova(retrain.mod2,retrain.mod1)
Analysis of Variance Table

Model 1: achieve ~ iq + age + method
Model 2: achieve ~ trt
  Res.Df    RSS Df Sum of Sq      F Pr(>F)
1     11 52.333                           
2      9 36.000  2    16.333 2.0417 0.1857
>