摘要:KEY WORDS measurement error; experimental design; bone modeling surface ABSTRACT Histological analysis of craniofacial bone surfaces reveals microstructural features produced by the activity of bone modeling, as well as other features not related to normal growth (taphonomic alterations). Identifying the areas produced by cell activity and determining their total size and distribution may be subject to various sources of error. In this sense, the objective of this study is to evaluate intra-observer error in the analysis of microstructures corresponding to formation and resorption on craniofacial bone surfaces linked to bone modeling. To this end an experimental random complete block design with repeated measurements was performed using high-resolution replicas of the glabella, malar and maxilla observed at incident light microscope. The type and extension of each cell activity-formation and resorption-were registered. The results revealed the existence of trends in observations over time, as well as differences in the recognition by type of bone surface and region analyzed. In general, an increased consistency across repetitions in the observation of the type of activity and in the quantification of formation and resorption areas was recorded. It could also be observed that the traits associated to the activity of resorption and the regions with a steep topography, such as the maxillary region, are more difficult to analyze. These results provide a framework for assessing the reliability of paleohistological observations in future studies.