Alfalfa                 package:nlme                 R Documentation

_S_p_l_i_t-_P_l_o_t _E_x_p_e_r_i_m_e_n_t _o_n _V_a_r_i_e_t_i_e_s _o_f _A_l_f_a_l_f_a

_D_e_s_c_r_i_p_t_i_o_n:

     The 'Alfalfa' data frame has 72 rows and 4 columns.

_F_o_r_m_a_t:

     This data frame contains the following columns:

     _V_a_r_i_e_t_y a factor with levels 'Cossack', 'Ladak', and  'Ranger' 

     _D_a_t_e a factor with levels 'None'  'S1'  'S20'  'O7' 

     _B_l_o_c_k a factor with levels '1'  '2'  '3'  '4'  '5'  '6' 

     _Y_i_e_l_d a numeric vector

_D_e_t_a_i_l_s:

     These data are described in Snedecor and Cochran (1980) as an
     example of a split-plot design. The treatment structure used in
     the experiment was a 3times4 full factorial, with three varieties
     of alfalfa and four dates of third cutting in 1943. The
     experimental units were arranged into six blocks, each subdivided
     into four plots. The varieties of alfalfa (_Cossac_, _Ladak_, and
     _Ranger_) were assigned randomly to the blocks and the dates of
     third cutting (_None_, _S1_-September 1, _S20_-September 20, and
     _O7_-October 7) were randomly assigned to the plots.  All four
     dates were used on each block.

_S_o_u_r_c_e:

     Pinheiro, J. C. and Bates, D. M. (2000), _Mixed-Effects Models in
     S and S-PLUS_, Springer, New York.  (Appendix A.1)

     Snedecor, G. W. and Cochran, W. G. (1980), _Statistical Methods
     (7th ed)_, Iowa State University Press, Ames, IA

