We have investigated monatomic steps on Ag(111) by STM at different temperatures. At room temperature, the rough appearance of these steps is usually attributed to thermal step fluctuations. We have investigated the influence of the tip systematically. Applying a new test, we demonstrate that even subtle influences can lead to wrong results in statistical analysis.
Mugele, F. G., Rettenberger, A., Boneberg, J., & Leiderer, P. (1997). Step roughness on Ag(111) investigated by STM: a systematic study of tip influence. Surface science, 377-37, 62-65. https://doi.org/10.1016/S0039-6028(96)01352-0