In the project we raised up a new form of pictures for aircraft safety cards combing the 3-D true objects and 2-D illustration backgrounds to improve the intelligibility, and help passengers better follow the instructions when faced with emergencies.
We did some usability studies to improve our design. To test the validity of our design, we employed an eye-movement experiment. In the experiment, we designed the operability test , contextual Interview and the System Usability Scale (SUS).
40 participants finished the experiment. Based on the behavior performance, eye movement pattern and interview results, our new design was effective and accessible.
This project is a cognitive design research , and more information are shown in the full paper.
Fang, T., Li, H., Xie, Y., Peng, Z., Ma, Z., Zhu, C., & Gao, Z. (2016). Factors of Comprehensibility of Airline Safety Briefing Cards: An Eye Tracking Study. Chinese Journal of Applied Psychology, In Press
Factors of Comprehensibility of Airline Safety Briefing Cards: An Eye-tracking Study
Professor Zaifeng Gao
Designer & Researcher
March 2016 – June 2016
Eye movement Analysis
Usability Test Method
System Usability Scale
Aviation Accident Casualties 2004-2014
data source: Aviation Safety Network
Every year more than 20 aviation accidents happened, and caused 500+ casualties on average. Thus, how to improve aviation safety is significantly important.
Based on previous research, in civil aviation, passengers' comprehension of cabin safety information could guide their evacuation when facing emergency (Hsu, 2010). The investigation of NTSB showed, passengers who didn’t read the safety card got injured in aviation accidents threefold than who read.
For this reason, it is of great significance to improve the comprehensibility of airline safety briefing cards.
In terms of pictorials used on safety card, we found there were two-forms: illustrations and real photos.
They are different in the pictorial realism on content.
Accelerate the identification of important details by emphasizing crucial elements, making it outstanding from irrelevant details (Johnson, 1980)
Excesses of realism may interfere with the transmission of information, in many cases, the reduction of realistic detail in an illustration improve the instructional effectiveness of it ( Dwyer,1967 )
Deviation between illustrations and real situations may harm the scene cognition of individuals in the operation, while pictures help users to build mental models of manipulation procedures (Glenberg & Langston, 1992).
The safety card comprehensibility can be improved significantly by providing more realistic pictures and more logic steps in the guide (Schmidt & Kysor, 1987)
Previous empirical studies mainly focused on integrated realism of pictorials, ignoring the realism variation within different objects. In order to combine the strengths of illustrations and the matching superiority of pictures, we created a mixture presentation style.
Real Photos: High Realism
Illustrations: Low Realism
Mixture: Mid Realism
The mixture pictorial employs real pictures of crucial operating items and illustrations of irrelevant backgrounds. This new presentation style not only helps passengers to match the item between pictorials and realities, but also reduce the distraction from details.
1. Test pictorials were adapted from a currently used airline safety briefing card and redesigned into three presentation styles with different degrees of realism. To exclude irrelevant variables such as layout and text, we just show users photos or illustrations of every operation separately .
2. Materials were evaluated in a 5-member focus group (3 experienced passengers and 2 novice users of safety cards), and revised the contrast, brightness, hues and lines based on comments.
For example, users complained that colorless figures on the picture looked strange and distractive. Thus later they were colored.
A between subject design with pictorial realism of three levels (all-real, all-illustration, and mixture)
Scan copy of the original safety briefing card, which uses all real pictures.
Use the digital panel to draw the outline of original pictorials, then fill appropriate colors in Photoshop CS6 (no texture or shadow).
Replace the emergency operating items in the all-illustration style with real pictures.
The result of eye-tracking, mockup operation test, interviews as well as SUS
We used 8 contents that must appear on a sample safety briefing card.
Because information about the emergency evacuation is most important, yet has uniformly low comprehensibility, we selected "Life vest usage", " Oxygen mask usage" and " Safety door operations" as three target stimulus, while others were five distracted stimulus.
Those contents were serially presented individually in the experiment. In the result, we just analyzed data about target stimulus.
A total of 40 participants years were recruited from student population at Zhejiang University, and 4 of them were removed due to eye-movement data lost.
Mock-up cabin test accuracy, eye movement data and SUS scores were statistically analyzed by SPSS and EXCEL, and interview results were analyzed by Atlas.ti.
Firstly, we found that mixture groups had higher accuracy when operating items in the mock-up test in oxygen mask and safety door conditions (although were only significantly in the former condition).
It showed that new design could possibly help participants conduct correct actions following the instructions.
Then, we tried to analyze attention distribution over pictorials to investigate wether there was a difference in information processing between different group.
MOCK-UP CABIN TEST ACCURNCY
EYE MOVEMENT DATA
In the eye movement data analysis, the first fixation duration (FFD), fixation duration (FD), and fixation counts (FC) of AOI (area of Interest ) were used
The eye movement trajectory
Each circle is a fixation, and the radius shows the duration time
When analyzing the attention distribution when watching pictorials, we defined operative motions, safety equipments and arrows as key operation areas, for example, the safety vest devices in the pictorials.
The degree of attention to key operations were defined as the ratio of fixation time/counts of key operation areas and whole pages
In the oxygen mark and safety entrance condition, both fixation duration ratio and fixation counts ratio of mixture group were significantly higher than others.
The heat map showed the difference directly.
Based on the heat map and statistic analysis, we found that mixture design helped participants to pay more attention on the key operation area. For example, in the heat map of safety gate, participants gazed more at the operative details such as observation windows and entrance pull rod.
We believed that, mixture design improved the comprehensibility of safety cards by reducing irrelevant details in background which would interfere with the attention of the participants.
HEAT MAPS OF FIXATION DURATION
fixation duration ranges from pure green at the low end, through yellow in the middle, to pure red at the high end.
Based on Grade Scale Standard, when scores of SUS are higher than 50,9, the usability is acceptable. Except safety gate, scores of the mixture group were both above 50.9.
Combining with interview results, it showed that users could accept this new design and would not feel strange or uncomfortable about the mixture of illustrations and photos.
The low scores of safety gate was caused by high complicated operation steps while excessive simple instructions, which should be improved soon.
INTERVIEW RESULTS ANALYZE
In civil aviation, passengers' comprehension of cabin safety information could guide their evacuation when facing emergency (Hsu, 2010). For this reason, it is of great significance to improve the comprehensibility of airline safety briefing cards.
This study created a new mixture presentation style of briefing pictorials, which employed real pictures of crucial equipment mixed with illustrations of irrelevant backgrounds, and conducted a comparative study with two exist illustration and real picture styles. When set independent variables as pictorial realism (all- real, all-illustration, and mixture), we compared users' eye-movement patterns, operating performances and subjective usability evaluation of pictorials in those three conditions. The result showed that, the mixture style could efficiently decrease the attention distraction caused by irrelevant details, and help passengers performing well in emergency manipulations. The study proved that the brand new design could truly improve the comprehensibility of airline safety briefing cards, and be well accepted by passengers.