We investigated the magnetoconductivity Delta sigma(H,T) defined by a function of magnetic field H and temperature T for three-dimensional indium-gallium-zinc oxide films in the resistivity rho range of 0.076 x 10(-3) Omega m <= rho(2.0 K) <= 0.55 x 10(-3) Omega m. Here, Delta sigma(H, T) is the Delta sigma(H, T) = 1 /rho(H,T) -1 /rho(0,T). With increasing rho, the contribution Delta sigma(EEI) due to the electron-electron interaction (EEI) effect overcomes the contribution Delta sigma(WL) due to the weak localization (WL) effect. The sign of Delta sigma(H) = Delta sigma(EEI) + Delta(WL) changes from positive to negative with increasing magnetic field, particularly at low temperatures. To perform a systematic investigation of Delta sigma(EEI), we obtained the contribution of Delta sigma(EEI) using the relation Delta sigma(EEI)(H, T) = Delta sigma(exp.)(H,T) - Delta sigma(theo.)(WL)(H, T), where Delta sigma(theo.)(WL)(H, T) is estimated by fitting the WL theory to data at low magnetic fields. It was found that i) Delta sigma(EEI)(H, T)/root T as a function of H/T for each film collapses onto a single universal curve at a magnetic field of up to 5 T and in the temperature range between 2.0 and 50 K. ii) From the analyses of Delta sigma(EEI)(H, T)/root T in the high and low H/T regions with the EEI theory, the screening factors F-Delta sigma,F-H and F-Delta sigma,F-L were estimated, respectively. iii) The F-Delta sigma,F-H values satisfy the theoretical prediction as 0 < F < 1. iv) With increasing rho, the magnitudes of both F-Delta sigma,F-H and F-Delta sigma,F-L essentially decrease to approach 0 at rho(c) approximate to 1.3 x 10(-3) Omega m, where the metal-insulator transition is suggested to occur. (C) 2013 Elsevier B. V. All rights reserved.