## 2 Methodology
### Procedure  
The participant joined trials for both picking by paper and picking using one of the two AR devices. A total of 20 boxes were picked up in each trial, with or without an AR device. This included 3 large, 7 medium-sized, and 10 small boxes. For the picking-by-paper trials, the participant received a paper list (see Table 2) and a trolley at the origin. They read the list and proceeded to the storage areas. The participant confirmed the text-based code numbers on the boxes, picked them up, and placed them on the trolley. They then continued to find the next box. Once all the listed boxes were collected and were on the trolley, the participant pulled the trolley back to the origin. An experimenter checked the boxes on the trolley and recorded the number of incorrect boxes collected. The time to accomplish the task, from leaving the origin with the empty trolley to returning to the origin with the fully loaded trolley, was measured using a stopwatch. For order picking using an AR device, all the participants received brief training on the use of each of the AR glasses before their first trials using an AR device. The participants learned to read virtual images on the glasses and to activate a QR code reader for all the AR glasses. Figure 4: An example of an order map showing the locations of the boxes to be picked and picking sequence. Figure 5: An example of a 3D graph showing the locations of the boxes to be picked. For the QR code picking, the participant wore a set of AR glasses and stood at the origin with an empty trolley. They scanned the activation QR code attached on the side of shelf AA to read the information of the first box to be picked (see Figure 6). The box location information, including the zone, shelf, row, column, and codes, similar to the code information in Table 3, was displayed in the AR glasses. The participant walked to the first shelf to find this box and scanned the QR code on the box to confirm the codes of both this box and the code of the next box to collect (see Figure 7). The participant picked up the current box and put it on the trolley and then walked to find the next box. Upon picking up the last box, a \"picking task has completed\" message appeared in the AR display. The participant then pulled the trolley and returned to the origin. An experimenter checked the boxes on the trolley and recorded the number of incorrect boxes picked up. Each participant performed the QR code picking task using each of the AR glasses. The boxes to be picked for the two AR glasses were different and their locations on the shelves were randomly arranged. For the order map and 3D graph order-picking tasks, the participants wore a set of AR glasses and stood at the origin with an empty trolley. They walked to shelf AA and activated the order map or the 3D graph by scanning the initial QR code. Once the order map or the 3D graph was activated and displayed on the AR glasses (see Figures 4 and 5), the participants could see the highlighted boxes and then walked to the shelves to find them. They could manipulate the order map and rotate the 3D graph by touching the touchpad on the M400  
\begin{table} \begin{tabular}{c c c c} \hline \hline
**Shelf** & **Locations** & **Codes** & **Mark** \\ \hline BB & R1-C5 & B-BB-015 & \\ \hline AB & R3-C2 & A-AB-032 & \\ \hline AC & R2-C3 & A-AC-023 & \\ \hline BC & R3-C4 & B-BC-034 & \\ \hline BB & R4-C1 & B-BB-041 & \\ \hline AA & R4-C3 & A-AA-043 & \\ \hline BD & R1-C2 & B-BD-012 & \\ \hline AD & R3-C5 & A-AD-035 & \\ \hline AA & R2-C1 & A-AA-021 & \\ \hline BA & R2-C5 & B-BA-025 & \\ \hline \hline \end{tabular}  Note: Each list included 20 boxes and only 10 of them are shown in this table. R and C are the row and column on the shelves, respectively. Box codes indicate the shelf number and box positions. A \(\  
device or using hand gestures when wearing the HoloLens 2, in order to have the best view in different areas.