Early                 package:mlmRev                 R Documentation

_E_a_r_l_y _c_h_i_l_d_h_o_o_d _i_n_t_e_r_v_e_n_t_i_o_n _s_t_u_d_y

_D_e_s_c_r_i_p_t_i_o_n:

     Cognitive scores of infants in a study of early childhood
     intervention.  The 103 infants from low income African American
     families were divided into a treatment group (58 infants) and a
     control group (45 infants).  Starting at 0.5 years of age the
     infants in the treatment group were exposed to an enriched
     environment. Each infant's cognitive score on an age-specific,
     normalized scale was recorded at ages 1, 1.5, and 2 years.

_U_s_a_g_e:

     data(Early)

_F_o_r_m_a_t:

     This 'groupedData' object contains the following columns

     _i_d An ordered factor of the id number for each infant.

     _c_o_g A numeric cognitive score.

     _a_g_e The age of the infant at the measurement.

     _t_r_t A factor with two levels, '"N"' and '"Y"', indicating if the
          infant is in the early childhood intervention program.

_R_e_f_e_r_e_n_c_e_s:

     Singer, Judith D. and Willett, John B. (2003), _Applied
     Longitudinal Data Analysis_, Oxford University Press. (Ch. 3)

_E_x_a_m_p_l_e_s:

     str(Early)

