Chem97                package:mlmRev                R Documentation

_S_c_o_r_e_s _o_n _A-_l_e_v_e_l _C_h_e_m_i_s_t_r_y _i_n _1_9_9_7

_D_e_s_c_r_i_p_t_i_o_n:

     Scores on the 1997 A-level Chemistry examination in Britain. 
     Students are grouped into schools within local education
     authories.  In addition some demographic and pre-test information
     is provided.

_U_s_a_g_e:

     data(Chem97)

_F_o_r_m_a_t:

     A data frame with 31022 observations on the following 8 variables.

     _l_e_a Local Education Authority - a factor

     _s_c_h_o_o_l School identifier - a factor

     _s_t_u_d_e_n_t Student identifier - a factor

     _s_c_o_r_e Point score on A-level Chemistry in 1997

     _g_e_n_d_e_r Student's gender

     _a_g_e Age in month, centred at 222 months or 18.5 years

     _g_c_s_e_s_c_o_r_e Average GCSE score of individual.

     _g_c_s_e_c_n_t Average GCSE score of individual, centered at mean.

_D_e_t_a_i_l_s:

     This data set is relatively large with 31,022 individuals in 2,280
     schools.  Note that while this is used, illustratively, to fit
     Normal response models, the distribution of the response is not
     well described by a Normal distribution.

_S_o_u_r_c_e:

     <URL: http://multilevel.ioe.ac.uk/softrev/chem97.html>

_R_e_f_e_r_e_n_c_e_s:

     Yang, M., Fielding, A. and Goldstein, H. (2002). Multilevel
     ordinal models for examination grades (submitted to _Statistical
     Modelling_).

_E_x_a_m_p_l_e_s:

     str(Chem97)
     summary(Chem97)
     (fm1 <- lmer(score ~ (1|school) + (1|lea), Chem97))
     (fm2 <- lmer(score ~ gcsecnt + (1|school) + (1|lea), Chem97))

