Examining the outdoor monitor’s effect and screen size on people's attention

1. The Effect of Outdoor Monitor on People’s Attention
Chau Tran1
, Ahmad Bilal Aslam1
, Waqas Hameed1
, Islam Tariq1
,
1
Faculty of Computer Sciences, Østfold University College
B R A Veien 4, 1757 Halden, Norway
{Chaut, Ahmad.B.Aslam, Muhammad.W.Hameed, Islam.Tariq}@hiof.no
Abstract. Since the end of 2019, COVID-19 has left several impacts on people’s
life. To reduce the chance of infection, avoiding crowded places has been recom-
mended by the authority. It raises a need to find an effective way to avoid high
occupancy levels inside public places. One approach is using a screen located
outside to display the occupancy information. This study aims to examine this
method’s effect and screen size on people's attention. To evaluate, various screen
sizes were investigated in a natural arrangement meaning that people's activities
and behaviors are observed and captured. The results show that placing a monitor
outside is a sufficient way to inform customers about the occupancy's level; and
the larger screen size increases the chance of getting people’s attention. The re-
search questions are implied in the sentence above. Our findings benefit those
seeking a suitable solution to provide the occupancy level of the public places.
Keywords: Human-Computer Interaction (HCI) · COVID-19 · Social Distance
· Outdoor Monitor · People’s attention · Crowd Monitoring System · Affective
aspects
1 Introduction
After the first coronavirus outbreak in Wuhan at the end of 2019, the World Health
Organization had stated a public health emergency of international concern on January
20, 2020, later declared it as a pandemic on March 11, 2020 [1]. COVID-19 has left
several impacts on human life as well as global economic, political, and social culture.
According to [2], this situation has changed the behavior of consumers and businesses
in different industries such as retail, higher education, and tourism. To reduce the spread
of COVID-19, the government has introduced various restrictions and regulations that
include keeping social distancing and avoiding crowded places. Those rules lead to a
need in finding an efficient way to provide the occupancy level of public places.
There are two primary tactics for displaying the number of occupied people, which
are manual and automated. The first approach is manual by using a person as a counter
and informer, while the other implements a system to monitor and transfer information
to a peripheral device such as a mobile application or an outdoor monitor. In the context
of the later solution, this study aims to examine its efficiency on people’s attention and
define the sufficient size of the screen.
The research describes how to design an outdoor display to provide occupancy’s
levels and capture people’s attention in the next four sessions, which follows the “User-
Centered Design” concept. It comprises a collection of processes that focus on putting

2. users at the center of product design and development. They are Informing in session
3, Designing & Prototyping in session 4, and Evaluation in session 5. Lastly, the con-
clusion and future work are provided in session 6.
2 Background
2.1 Literature Review
The first display was invented in 1897 by Karl Ferdinand Braun, a physicist, and in-
ventor using Cathode-Ray Tube. However, before becoming a popular and comprehen-
sive device as of today, it had taken decades of research and innovation in technology
[3]. Since then, the display screen has changed the way information is absorbed. For
instance, this invention has shifted the reading habit from paper to electronic books,
especially with e-ink. Thus, it helped to generate a similar result between e-readers and
printed paper [4]. Furthermore, [5-7] studied leveraging the screen feedback to the
teaching suprasegmental regarding stress, rhythm, linking, and intonation. It convinces
that applying electronic visual display can alter people’s behavior.
In the last decade, there have been various studies focused on the effect of the dis-
play’s size. Their motivation is driven by the growth of screen diversity and the interest
in user experience. Despite the contradiction in research findings, there is thorough
support that the large screen promotes attention and memory. [8] showed that there
were a higher heart rate deceleration and skin conductance created by the largest screen
(56-inch) compared to the medium and small ones. Thus, their hypothesizes were
proven that users had paid more attention and been more arousing when using larger
screens. The work from [9] assessed the impact of variation monitors on text memoriz-
ing. Although there were no differences in the required cognitive effort of the acquired
information between screen size or text layout, there was a significant effect on learning
time. Students reading from 15-inch computer learned faster than from smaller one of
12-inch. Moreover, viewers were preferring to watch a large monitor when it came to
the point-of-view movement such as video, compared to images [10]. Also, their review
found that using a bigger screen can reduce the mindful consideration of the persuasive
contents or education messages. Therefore, those studies strengthen the potential im-
pact of outdoor display’s size on people’s attention and actions before entering public
places during COVID-19 situation.
2.2 Research Questions and Hypotheses
Based on the review of past literature, this research tries to answer two concerns: (1)
how outdoor monitor helps people obligate to the guidance; (2) how monitor’s size
affects people’s attention. They can be represented as two hypotheses, which are stated
as follows:
H1: A public display system increases the likelihood that people follow room
occupancy guidelines.
H2: The bigger size of the screen produces a higher chance of grabbing people’s
attention.

3. 3 Informing
3.1 Method
To have a better understanding of users’ opinion of a public display system containing
occupancy level, a survey was conducted which consisted of two sessions: an online
questionnaire and an interview. 14 volunteers participated in the experiment. Several
questions had been asked such as:
• In this pandemic, how did they feel when they enter a crowded place like a gro-
cery store?
• Were they in favor of placing a public display informing them about the occu-
pancy level inside a grocery store?
• If such a system is designed, would they like to have any sort of tangible inter-
action with it?
• What information would they think should be displayed by a crowd monitoring
system?
The answer to these questions shows the user’s need, perspective, and expectation
for the proposed system.
3.2 Result
The survey conducted in the informing stage revealed that the participants had a high
frequency of visiting the grocery store. Moreover, their feelings were uncomfortable
when entering a crowded place. Almost 80% of the people considered it necessary to
put a display screen outside the shop because it helps to keep an update about the crowd
situation inside the grocery store. They also suggested keeping the information simple
so it is easier to comprehend. Lastly, three fourth of the people did not want any phys-
ical interactions with the display screen because of the risk of being infected by
COVID-19.
4 Designing & Prototyping
4.1 Method
The general perception of colors is that red can be pivotal in depicting alarming condi-
tions and green for depicting safety situations [11]. Considering this relationship, the
red color was used in design to alert people when the threshold (max number of people
allowed) was met. On the contrary, the green color was used to let people know that it
was safe for them to enter the public space. The feedback from the participants is con-
sidered that the design should be simple and have relevant information. A study sug-
gested the people apprehend graphical information more than numerical information
therefore the designs also include a bar displaying the capacity making it a better expe-
rience for users [12].

4. Since the focus of the study was mainly on interaction design, more emphasis was
given to display and user experience. Thus, different sketches were created followed
this direct.
4.2 Result
After performing the literature review and conducting the survey, two final designs are
presented in this session. Fig. 1 illustrates the “Allowed” design when the occupancy
level is below the threshold whereas Fig. 2 shows the “Not Allowed” design which
instructs people to wait.
Fig. 1. "Allowed” design informing that people can enter.
Fig. 2. "NOT Allowed” design informing that people cannot enter.
5 Evaluation
5.1 Method
To evaluate the hypotheses, an experiment was carried out in a natural setting, which
means the participants’ actions were observed without controlled scripts during the
study. Three different screen sizes being used for implementing the observation were
45-inch, 32-inch, and 24-inch. The test was organized at an entrance of the university
cafeteria with the place capacity’s limitation being at 15. The participants were chosen
randomly regarding their age, their gender, or their nationality. To examine the two
hypothesizes, two scenarios were orchestrated based on the Wizard of Oz method. It
means the screen’s responses are being generated by a human without the subject’s
awareness.

5. For the first scenario, observations were made on the behavior of each participant
whether the subject looks at the display and follows the instruction or not. A wireless
remote was used to change the occupancy’s level on the screen by different designs.
Whenever a person enters the cafeteria, the design is updated on the screen to increase
the number of inside people and vice versa. If the limitation is reached, the “NOT al-
low” sketch displays the expected behavior is shown in Fig. 3.
For the second scenario, observations were to be made on participant’s behavior
when passing within the 25-foot radius of the entrance, whether they took a glance at
the display or not. Three different screen sizes were used for this test. The screen is
changed after the number of subjects reaches 25.
Fig. 3. Screen setup outside the cafeteria.
5.2 Result
5.2.1 The first experiment
Regarding the data analysis, a binomial test is implemented with the input values being
listed in Table 1. It includes the number of successes (k=26), the total number of trials
(N=30), and hypothesized probability (p=0,5). The outcome result is the exact proba-
bility of success being recorded as 0.87. Also, the p-value from binomial test is less
than 0.05 (p-value = 5.948e-05 < 0.05). Therefore, the null hypothesis is rejected lead-
ing to accept the first hypothesis, which means there is a higher chance of people fol-
lowing the outdoor screen information.
Table 1. The number of people following the outdoor screen guidance and its binomial
test values.
Screen Size Subject No Follow Not Follow p-value Exact proportion
45’’ 30 26 4 5.948e-05 0.87
5.2.2 The second experiment
To examine the collected data, a statistical method called proportion test was used,
which is based on the binomial distribution. After applying the binomial test, the exact
probability of success for 45’’, 32’’, and 24’’ respectively equal to 0.96, 0.88, and 0.60
listings in Table 2. Also, the p-value from the binomial test is 5.591e-08, which is

6. smaller than 0.05. It proves that there is a difference in the success proportions of three
screen size groups.
Moreover, the z test was conducted to define whether there is a significant difference
in the proportion between the two screens. The z-values in Table 3 record all positive
numbers indicating a reduction in the success probability when changing to smaller
screen size. It’s also noticeable that the p-value of the comparison 32’’ – 24’’ and 45’’
– 24’’ is less than 0.05 while the pair 45’’ – 32’’ is larger than 0.05. There is a significant
increase in probability from large and medium screens (45’’ or 32’’) to the small screen
(24’’). On the contrary, there is no differences between 45’’ and 32’’ screen. Thus, it
verifies that there is a rise in the number of people getting attention to the display when
increasing the screen size. Or the second hypothesis is accepted.
Table 2. The result of three different screens (45’’, 32’’, and 24’’) on people's attention
and its proportion test values.
Screen
Size
Subject
No
Notice
Hypothesized
probability of suc-
cess.
The exact
probability
of success
p-value
45’’ 25 (A) 24 0.5 0.96
5.591e-08
32’’ 25 (B) 22 0.5 0.88
24’’ 25 (C) 15 0.5 0.60
Table 3. The multiple comparison z tests between 2 screens.
Comparison z-value One-tailed
p-value
Note
45’’ – 32’’ 1.0426 0.14917 > 0.05
32’’ – 24’’ 2.2569 .01191 < 0.05
45’’ – 24’’ 3.0725 .00107 < 0.05
6 Discussion
In the interest of designing an outdoor display to present the number of occupancy and
grabbing people’s attention, this study organized a survey to define user’s need, opin-
ion, and expectation before designing a prototype. Then, two experiments were con-
ducted with a final sketch to identify the answer for two research questions, which are:
(1) whether placing a monitor outside is a sufficient way to inform customers about the
occupancy's level; and (2) what the effect of monitor’s size on people’s attention. The
first test examined the influence of a 45-inch screen on 30 participants, while the second
one used 3 different screens to explore if there was a proportional ratio between the size
and people’s notice.
Result analysis in evaluation session revealed that the p-value in binomial test and
z-test were less than 0.05; hence, the two proposed hypothesises are accepted. It con-
firms: a public display system increases the likelihood that people follow room occu-
pancy guidelines (H1), and the bigger size of the screen produces a higher chance of
grabbing people’s attention (H2). Therefore, an outdoor display is a useful and efficient
approach to inform users about the number of inside people, since information is

7. displayed on the screen in real-time and the data is continuously updating. Moreover,
it proves that larger screen size enhances people’s tendency to notice the information.
Also, it observed that the large screens catch passer-by’s attention and can be influential
in the advertisement. However, to conclude the ideal monitor size depends on various
factors including the dimensions of the entrance, locality, free space, or background.
These findings are tally with the previous works which were reviewed in the literature
review session.
Finally, the tests were conducted in an academic environment during COVID-19, so
the participants mostly have high education and self-aware of the situation. Therefore,
they are more obligative toward the restriction rule. The reliability of this study can be
improved by increasing the sample size with more participants and changing the exper-
iment environment.
7 Conclusion
In conclusion, two experiments are established to examine an outdoor display design in
the interest of the subject’s attention and behavior. The result shows that two proposed
hypotheses are accepted leading to some primary findings, which are:
• Placing an outdoor display increases the willingness of people to follow the in-
structions on the screen.
• The screen size influences people’s attention. A large screen has a higher suc-
cess chance than a smaller one.
• Because of no significant variations in the probability of getting people’s notice
between large and medium screens, a 32-inch screen is a more efficient choice
in terms of cost-saving.
Therefore, this study proves that the monitor system with an outdoor screen is an
efficient approach to inform customers about the occupancy level during the COVID-
19 situation.
8 Acknowledgment
The authors would like to thank Assoc. Prof. Georgios Marentakis for his guidance and
support throughout this project.
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