Test for
parameters equality in nonlinear regression models. I. Data in the randomized
complete design

Adair José REGAZZI^{[1]}

Carlos Henrique Osório SILVA^{1}

§ ABSTRACT: We considerer the
adjustment of g nonlinear regression equations and the likelihood ratio test
with c^{2 }approximation in order to test model identity,
and we also compare the approximations given by F and c^{2} test statistics in a simulation study. For
sufficiently large data sets (N ³ 120) we found the two approximations to
perform roughly the same. For smaller sample sizes the F statistic
approximation should be preferred since it yielded smaller type I error rates
for N values investigated.

§ KEYWORDS: Growth curve; likelihood;
hypothesis test.

[1] Departamento
de Informática, Universidade Federal de Viçosa - UFV, CEP 36570-000, Viçosa,
MG, Brasil. E-mail: * adairreg@
ufv.br / chos@dpi.ufv.br*.