Kappa                  package:vcd                  R Documentation

_C_o_h_e_n'_s _K_a_p_p_a _a_n_d _w_e_i_g_h_t_e_d _K_a_p_p_a

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

     Computes two agreement rates: Cohen's kappa and weighted kappa,
     and confidence bands.

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

     Kappa(x, weights = c("Equal-Spacing", "Fleiss-Cohen"), conf.level = 0.95)

_A_r_g_u_m_e_n_t_s:

       x: a confusion matrix.

 weights: either one of the two options or a user-specified matrix with
          same dimensions as 'x'.

conf.level: level for the confidence intervals.

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

     Cohen's kappa is the diagonal sum of the (possibly weighted)
     relative frequencies, corrected for expected values and
     standardized by its maximum value. The equal-spacing weights are
     defined by 1 - abs(i - j) / (r - 1), r number of colums/rows, and
     the Fleiss-Cohen weights by 1 - abs(i - j)^2 / (r - 1)^2. The
     latter ones attach greater importance to near disagreements.

_V_a_l_u_e:

     An object of class 'kappa' with three components: 

   Kappa: Kappa statistic, along with Approximate Standard Error (ASE)
          and 95% confidence bounds.

Kappa.Weighted: idem for the weighted kappa.

 Weights: weight matrix used.

_A_u_t_h_o_r(_s):

     David Meyer
      david.meyer@ci.tuwien.ac.at

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

     *  Cohen, Jacob (1960): A coefficient of agreement for nominal
        scales. Educational and Psychological Measurement.

     *  Everitt, B.S. (1968): Moments of statistics kappa and weighted
        kappa. The British Journal of Mathematical and Statistical
        Psychology.

_S_e_e _A_l_s_o:

     'agreementplot'

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

     data(SexualFun)
     Kappa(SexualFun)

