## 2 Materials and Methods
Then, in step 4, we demonstrated a proof-of-concept of our proposed calibration models. To meet the challenges inherent to industrial environments, the scenario defined for this stage was a logistics warehouse. This warehouse is approximately 10,000 m\({}^{3}\), contains a large variety of equipment and components, and has characteristics such as dynamism in the composition of its internal layout and variability in lighting, noise, and obstacles. The International Organization for Standardization (ISO) defines, in ISO 5725-1:2023, accuracy as the closeness of agreement between a test result and the actual value and precision as the closeness of agreement between independent test results obtained under stipulated conditions [19]. In step 5, we evaluated our proposed calibration models in terms of validity criteria, since DSR includes gathering evidence that the artifact is useful, meaning that the artifact works and does what it is intended to do [17]. To measure these indicators, two experiments were carried out. The first experiment was to verify and compare, in an industrial environment, the precision of the proposed two-step calibration model with a simple calibration model. The second experiment was to check if, in fact, the proposed model achieved the objective of locating and assisting in the identification of components within an industrial environment. To evaluate the precision (i.e., the dispersion of the samples) and accuracy (i.e., the exactness) of the simple and two-step calibrations in an industrial scenario, the prototype was programmed to perform each calibration separately so that, after the calibration step,it would be able to measure the virtual coordinates relative to the calibration system origin of markers placed in different locations within the scenario. To configure the experimental environment, five points were first selected inside the warehouse. The criteria for choosing these points were as follows:  
1. Locations that remained the same throughout the experiment. Changes in these locations would require measurements to be re-performed;
2. Locations where it was possible to measure with a laser tape measure from the point chosen as the origin to obtain a rigorous measurement (gold standard);
3. Locations at different distances from the point chosen as the origin;
4. Locations where all markers could be placed at the same height, facilitating data analysis;
5. Locations where the markers could be viewed from the front, with at least one meter of distance, so that the marker could be viewed by the HoloLens camera. Once the points were selected, one of them was defined as the origin, a fiducial marker was placed at this point, and the exact center of this marker was used as a reference for the position of origin of both the virtual and the real coordinate systems. In addition to these markers, an additional marker was added at the same height (y-coordinate) in the direction of the negative x-axis and 1.594 m away from the marker of origin. In general, the second fiducial marker should be aligned with the first. This last marker is used for two-step calibration. Lastly, with the laser tape measure, the x and z coordinates of the other markers were measured from the origin. Figure 1 shows the arrangement of the points within the scenario, as well as the measured coordinates of each point and the distance vector from the origin for each of the points. Finally, step 6 of the design science research approach entails communicating our findings in this work.