# Effect of Augmented Reality Support on Quality Inspection of Welded Structures
## 3 Materials and Methods
### Procedure
Once the inspection is complete, the results of the checklist are uploaded to the Firebase database, and if a deviation from the quality is captured, an annotation describing the deviation is added to the checklist before uploading. An example of the AR approach is shown in Figure 6.  
Figure 5: Workstation for conventional paper-based inspection. Both the G1 and G2 groups performed the control experiment using the described conventional approach and the proposed AR approach. In total, 50 pieces were inspected in the experiment, which included 10 types of products. One inspection set of 25 products was used for each tested approach. Both control sets included products comparable in complexity, design, and dimensions. They contained the same number of parts with the same error ratio. Group G1 first inspected one set with the AR approach, then the other set in the context of the conventional approach. Group G2 inspected the first set with the support of the conventional approach and then the second set using the proposed AR approach. Thus, all probands eventually inspected all parts, eventually using both inspection approaches. The individual parts came to the probands for inspection randomly. A brief training session was conducted at the beginning of each phase of the experiment. The participant was first briefly introduced to the process and the operation of the AR application or the structure of the paper-based inspection documentation. Subsequently, the user was given time to test the functions of the AR software. It was explained to the probands how the experiment would proceed, and they were instructed to perform the checks in the shortest possible time while being as accurate as possible with the least number of errors. This phase lasted 5-10 min. The main phase of the experiment, i.e., the inspection of the two control sets, was then carried out. The results from the AR application were continuously uploaded directly to the Firebase database, while paper results were collected at the end of the process. Time was tracked, and feedback and comments from probands were collected during the control. After completing the review of the first 25 pieces, probands were asked to complete the NASA TLX (Task Load Index) questionnaire to rate the mental workload they perceived during the process. They then proceeded to check the second set of 25 parts. After completing this part, they again completed the NASA TLX. In addition, probands completed the SUS (System Usability Scale) questionnaire, in which they rated the usability of the proposed approach, and an anonymised questionnaire, in which they provided information about their age, gender, work experience, their relationship with IT and technology, and their experience with AR and VR. Subsequently, an interview was conducted with each proband to find out their opinion about the experiment conducted, which method they would prefer in their daily work, how they rate the clarity and potential of each approach, and what they see as the advantages, disadvantages, and limitations of each approach.