ability.cov             package:datasets             R Documentation

_A_b_i_l_i_t_y _a_n_d _I_n_t_e_l_l_i_g_e_n_c_e _T_e_s_t_s

_D_e_s_c_r_i_p_t_i_o_n:

     Six tests were given to 112 individuals. The covariance matrix is
     given in this object.

_U_s_a_g_e:

     ability.cov

_D_e_t_a_i_l_s:

     The tests are described as

     _g_e_n_e_r_a_l: a non-verbal measure of general intelligence using
          Cattell's culture-fair test.

     _p_i_c_t_u_r_e: a picture-completion test

     _b_l_o_c_k_s: block design

     _m_a_z_e: mazes

     _r_e_a_d_i_n_g: reading comprehension

     _v_o_c_a_b: vocabulary

     Bartholomew gives both covariance and correlation matrices, but
     these are inconsistent.  Neither are in the original paper.

_S_o_u_r_c_e:

     Bartholomew, D. J. (1987) _Latent Variable Analysis and Factor
     Analysis._ Griffin.  

     Bartholomew, D. J.  and Knott, M. (1990) _Latent Variable Analysis
     and Factor Analysis._ Second Edition, Arnold.

_R_e_f_e_r_e_n_c_e_s:

     Smith, G. A. and Stanley G. (1983) Clocking g: relating
     intelligence and measures of timed performance. _Intelligence_,
     *7*, 353-368.

_E_x_a_m_p_l_e_s:

     require(stats)
     (ability.FA <- factanal(factors = 1, covmat=ability.cov))
     update(ability.FA, factors=2)
     update(ability.FA, factors=2, rotation="promax")