  The nucleon form factors are calculated using a non-relativistic description
in terms of constituent quarks. The emphasis is put on the reliability of
present numerical methods used to solve the three-body problem in order to
correctly reproduce the expected asymptotic behavior of form factors. Nucleon
wave functions obtained in the hyperspherical formalism or employing Faddeev
equations have been considered. While a q**(-8) behavior is expected at high q
for a quark-quark force behaving like 1/r at short distances, it is found that
the hypercentral approximation in the hyperspherical formalism (K=0) leads to a
q**(-7) behavior. An infinite set of waves is required to get the correct
behavior. Solutions of the Faddeev equations lead to the q**(-8) behavior. The
amplitude of the corresponding term however depends on the number of partial
waves retained in the Faddeev amplitude. The convergence to the asymptotic
behavior has also been studied. Sizeable departures are observed in some cases
at squared momentum transfers as high as 50 (GeV/c)**2. It is not clear whether
these departures are of the order 1/q or 1/q**2 log q relatively to the
dominant contribution and whether the bad convergence results from truncations
in the calculations. From a comparison with the most complete Faddeev results,
a q**2 validity range is obtained for the calculation made in the
hyperspherical formalism or in the Faddeev approach with the minimum number of
amplitudes.
