Journal of Applied Sciences1812-56541812-5662Asian Network for Scientific Information10.3923/jas.2011.3328.3332ShadrokhAli 1220111118Tests of significance of a single partial regression coefficient in a multiple regression model are often made in situations where the standard assumptions underlying the probability calculation (for example assumption of normally of random error term) do not hold. When the random error term fails to fulfill some of these assumptions, one need resort to some other nonparametric methods to carry out statistical inferences. Permutation methods are a branch of nonparametric methods. This study compared empirical type one error of different permutation strategies that proposed for testing nullity of a partial regression coefficient in a multiple regression model, using simulation and show that the type one error of Freedman and Lanes strategy is lower to than the other methods.]]>Al-Salihi, A.M., M.M. Kadum and A.J. Mohammed,20103240248Anderson, M.J. and P. Legendre,199962271303Bizhannia, A.R., S.Z. Mirhosseini, B. Rabiee and M. Taeb,2010Bombyx mori L.).]]>94147Bughio, H.R., A.M. Soomro, A.W. Baloch, M.A. Javed and I.A. Khan et al.,20021439440Edriss, M.A., P. Hosseinnia, M. Edrisi, H.R. Rahmani and M.A. Nilforooshan,20083222229Fisher, R.,1935lst Edn.,Freedman, D. and D. Lane,19831292298Huh, M.H. and M. Jhun,20013020232032Kandhro, M.M., S.Laghari, M.A. Sial and G.S. Nizamani,2002Gossypium hirsutum L.) developed through induced mutation and hybridization.]]>1581582Kennedy, P.E. and B.S. Cade,199625923936Laghari, S., M.M. Kandhro, H.M. Ahmed, M.A. Sial and M.Z. Shad,2003Gossypium hirsutum L.) genotypes.]]>2480482Manly, B.F.J.,19912nd Edn.,Rashid, A., G.R. Hazara N. Javed, M.S. Nawaz and G.M. Ali,20025591592Serhat Odabas, M., Sezgin Uzun and G. Ali,2007Vicia faba L.): I. Growth.]]>2765775Shadrokh, A. and G. d 'Aubigny,20104857878Shadrokh, A.,20112011Tariq, M., M. Irshad-ul-Haq, A.A. Kiani and N. Kamal,200328082Ter-Braak, C.J.F.,19921992pp: 79-86pp: 79-86Alam, M.Z.,20043200204