On Fri, 22 Jan 2010 07:03:07 -0800 (PST), Zidavora Elena <elena.zidarova@googlemail.com> wrote: >Hello, > >Does somebody have any suggestions why AMOS provides the following >message in the output? > >"Notes for Model (Default model) > >Computation of degrees of freedom (Default model) >Number of distinct sample moments: 55 >Number of distinct parameters to be estimated: 23 >Degrees of freedom (55 - 23): 32 > >Result (Default model) > >Iteration limit reached >The results that follow are therefore incorrect. >The model is probably unidentified. In order to achieve >identifiability, it will probably be necessary to impose 1 additional >constraint." > > >Is it possible to have both a positive number of degrees of freedom >and a model which is unidentified? How can i fix the problem? > >I will really appreciate your help. Thanks. One key phrase is probably "Iteration limit reached." I've never used AMOS, but by analogy with its simpler cousin, factor analysis, I conclude that a solution did not converge adequately within the given number of steps. Presumably, you can increase the number of steps by stating "ITERATIONS=" . However, slow convergence also seems to indicate that *these* data do not provide a substantial difference between alternative latent structures, so that simplifying the model (additional constraints) may be a good idea even if changing ITERATIONS lets AMOS crank out a solution. You might also check your data again for such things as miscoded data or other natural outliers that might underlie the difficulty in obtaining a fit. -- Rich Ulrich

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1/22/2010 8:14:20 PM