4.1 This compilation is limited to artifacts observed in scanning tunneling microscopes and contact-mode atomic force microscopes. In particular, this document focuses on artifacts related to probe motion and geometrical considerations of the tip and surface interaction. Many of the artifacts described here extend to other scanned probe microscopies where piezoscanners are used as positioning elements or where tips of similar geometries are used. These are not the only artifacts associated with measurements obtained by STM or AFM. Artifacts can also arise from the following: control electronics (for example, improper feedback gains); noise (mechanical, acoustic, or electronic); drift (thermal or mechanical); problems unique to signal detection methods (for example, laser spillover in optical lever schemes); improper use of image processing (real time or post processed); sample preparation, environment (for example, humidity) and tip-surface interaction (for example, excessive electrostatic, adhesive, shear, and compressive forces). It is suggested that these other types of artifacts form the basis of future ASTM guides.