## 2 Materials and Methods
### Determination of Relevant Visual Information  
Nine GoPro cameras (Hero Session, with horizontal field of view of 120\({}^{\circ}\) and a video resolution of 1920 \(\times\) 1440) were mounted at different locations on a high clearance, self-propelled agricultural sprayer (Rogator 1100) to capture video footage of various regions of the sprayer and its environment while the sprayer was in operation (Figure 2). Various literature sources [14; 15; 17] were consulted to position the GoPro cameras on the sprayer. The rationale for the positioning of each camera is provided in Table 1. Some cameras were positioned to provide familiar views (i.e., look zones that a sprayer operator would typically see from the seated position), while other cameras were positioned to provide non-traditional views (i.e., look zones that are not visible from the seated position). Video recording was completed on the morning of 6 July 2017 on a flat field near Rosser, MB (137 acres in size). Video duration was approximately 42 min (which was the time required to spray the entire field). On a separate occasion (21 July 2017), video was recorded from a drone to provide an overhead view of the entire sprayer. A third party licensed drone operator assisted in capturing the overhead view on a field near Moosehorn, MB (120 acres in size); video was recorded for approximately 11 min and covered only a portion of the spraying operation. Subsequent to collection of the video footage, clips of approximately 60 s in duration were selected from the full video, which showed a large variation in the spraying operation, the sprayer's operational status, and the field or environmental conditions. Experienced sprayer operators (defined as having at least two years of experience operating a sprayer) were recruited from the prairie provinces (Manitoba, Saskatchewan, and Alberta) through industrial partners (Northstar Robotics), university, and farmers' group contacts to participate in this phase of the research. Participants had the choice to either come in person to the Agricultural Ergonomics Lab at the University of Manitoba to complete the experiment or to complete the study online. All participants were required to give their consent prior to the commencement of the experiment. After answering demographic questions, participants were required to view a series of video clips and complete a questionnaire consisting of six questions. In total, eleven  
Figure 2: A schematic drawing showing the various camera positions on the sprayer during the first phase of the project: (**a**) plan view; (**b**) side view. Cameras were placed on each dot, while arrows indicate the direction of the camera. Note: camera P = clip P; camera 1 = clip 1; camera 2 = clip 2. Camera 5 was mounted on a drone, while cameras 8 and 9 were third party hand-held cameras that were focused on the back of the sprayer and the field, respectively. Camera M was placed inside the sprayer’s cab to record the head and eye movement of the operator. video clips were presented to each participant: one practice clip (clip P) and ten test clips (clips 1-10). The practice clip was included to allow participants to familiarize themselves with the experimental protocol and the questions that followed each video. Video clips showing familiar views of the sprayer and its environment (from the operator's seated position) were presented before non-traditional views. The video clip questionnaire comprised six questions. The first three questions were open-ended and required participants to describe: (i) what they saw in each video clip, (ii) the information gained from each video clip, and (iii) how they could use such information during operation of the sprayer. The fourth question asked if the video clip was something the operator typically viewed when operating a sprayer (yes/no response) and whether such a view is useful to the spraying operation (yes/no response). Question 5 required the participant to rank the importance of the visual information perceived using a 5-point Likert scale.