coefH                 package:mokken                 R Documentation

_S_c_a_l_a_b_i_l_i_t_y _c_o_e_f_f_i_c_e_n_t_s _H

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

     Computes item-pair scalability coefficents Hij, item scalability
     coefficents Hi,  and scale scalability coefficent H

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

     coefH(X)

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

       X: matrix or data frame of numeric data  containing the
          responses of 'nrow(X)' respondents to 'ncol(X)' items. 
          Missing values are not allowed

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

     Does not work if any of the item variances equals zero.  Such
     items should not be used in a test and removed from the data
     frame.

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

     Hij: matrix containing scalability coefficients of the item pairs

      Hi: vector containing scalability coefficients of the items

       H: scalability coefficient of the entire scale

_N_o_t_e:

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

     L. A. van der Ark a.vdark@uvt.nl

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

     Mokken, R. J. (1971)  _A Theory and Procedure of Scale Analysis_. 
     Berlin, Germany: De Gruyter.

     Molenaar, I.W. and Sijtsma, K. (2000)  _User's Manual MSP5 for
     Windows_ [Software manual]. Groningen, The Netherlands: IEC
     ProGAMMA.

     Sijtsma, K, and Molenaar, I. W. (2002) _Introduction to
     nonparametric item response theory_. Thousand Oaks, CA: Sage.

     Van der Ark, L. A. (2007).  Mokken scale analysis in 'R'. 
     _Journal of Statistical Software_. <URL: http://www.jstatsoft.org>

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

     'coefZ', 'search.normal'

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

     data(acl)
     acl.com <- acl[,1:10]
     coefH(acl.com)

