The plotting of data against position along a traverse line, to produce a display of resistivity or induced-polarization data in which values are given to the intersection point of 45° lines drawn from mid-points of the current and potential electrode pairs. Depths in the resulting ‘section’ below a transverse bear no simple relationship to the true geology; a pseudosection shows the variation of the measured parameter with position and with effective depth of penetration, rather than with true depth. It is used widely in displaying induced-polarization data and apparent resistivities obtained from constant-separation traverses with different electrode separations, and apparent conductivities from electromagnetic traverses with different coil separations.