Detailed characterization of graphene oxide (GO) and its reduced forms continues to be a challenge. We have employed scanning tunneling microscopy (STM) to examine GO samples with varying degrees of deoxygenation via controlled chem. redn. Anal. of the roughness of the apparent height in STM topog. measurements, i.e. the äpparent roughness\", revealed a correlation between increasing deoxygenation and decreasing apparent roughness. This anal. can therefore be a useful supplement to the techniques currently available for the study of GO and related materials. The presence of a high elec. field underneath the STM tip can locally induce a reaction on the GO basal plane that leads to local deoxygenation, and the restoration of the sp2 hybridization of the carbons promotes increased planarity. These findings are in line with the apparent roughness values found for GO at varying levels of chem. redn. and illustrates the value of having a tool to gain structural/chem. insight on a local scale. This is the first example of employing an STM tip to locally reduce GO to reduced GO (rGO) and partially reduced GO (prGO) without locally destroying the graphene sample. Local manipulation on the nanoscale has utility for graphene nanoelectronics, and anal. employing the apparent roughness is an addnl. tool for the study of graphene oxide and related basal plane chem. [on SciFinder(R)]