EFFECTIVENESS OF A TABLET-PC-BASED SAFETY-TRAINING TOOLFOR CONSTRUCTION WORKERS- AGE-RELATED COMPARISON
Akiko Takahashi,1 Motoya Takagi,1 Makoto Mishina,2
Kan Shimazaki,3 and Toshiro Ishida3
1

National Institute of Occupational Safety and Health, Japan, 1-4-6 Umezono, Kiyose
Tokyo 204-0024, Japan
2
Cyvision, Ltd., 4-17-8 Kaminoge, Setagaya Tokyo 158-0093, Japan
3
Waseda University, 2-579-15 Mikajima, Tokorozawa Saitama 359-1192, Japan

This study seeks to create a tablet-PC-based safety-training tool for residential
construction workers and to compare the tool’s effectiveness by age. The tool
displays four work situations on a tablet PC, including one dangerous situation.
Participants choose one dangerous situation from these and learn dangerous
situations by repetition. Seventy construction workers participated; they weredivided into three groups by age (young, middle-aged, and older). Results indicatedthat the percentage of correct answers increased for all three groups. Furthermore,
the time required for all groups to judge dangerous situations decreased; theseresults suggest that all groups came to understand the dangers and focused on themmore quickly, and that the tool was effective in facilitating comprehension of
curriculum content. However, the tool was less effective for the older group than forthe other two groups, suggesting the need to improve the tool for older workers.

Introduction
The revised Industrial Safety and Health Law of 2005 requires employers to identify hazards at
workplaces and evaluate risks, and to take action to reduce risks. In the construction industry, risk
assessment has been promoted in order to prevent work-related accidents. However, even if
employers take action to reduce risks at the workplace, it is difficult to reduce risks to a tolerable
level because the dynamic factors of the work environment change with the progress of work, andrisk varies depending on site. Therefore, it is important that workers themselves learn how toprevent accidents through safety programs and safety training. On Japanese construction sites,
workers often receive Kiken Yochi Training, which teaches them to predict hazards in theworkplace with team members before beginning work, in order to enhance risk awareness. However,
it is difficult to conduct such training on residential construction sites, since only one worker may be
at a worksite. Furthermore, an administrator cannot confirm whether the training is being utilized,
since worksites are spread over a wide area. Therefore, at residential construction sites it would be
useful to have a safety-training tool that a worker can use alone and that allows an administrator todetermine remotely whether training is being utilized.
Therefore, this study created a tablet-PC-based safety-training tool for construction workers.
When a worker is trained using this tablet PC, the data is automatically sent to a server via theInternet. By accessing this server from another location, administrators can understand and manage
the implementation of worker training.
This study seeks to implement safety training of workers with the tablet-PC-based safetytraining tool and to investigate the tool’s effectiveness empirically. Furthermore, this study focuseson the ages of the workers and compares the tool’s effectiveness by age.

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Method
Tablet-PC-based safety-training tool

Figure 1 depicts one trial of training using a tablet-PC-based safety-training tool. This trial
consisted of a “work situation” that explained in a sentence the work situation of the image to bepresented next, a “question” in which four images of work were presented simultaneously, andan “explanation” as to whether the image was incorrect or correct and an explanation. Of the four
images in “question,” a risk factor was included in only one of the images. After confirming the“work situation,” the participant touched as quickly as possible the image in which a risk factor
was included. At this time, reaction time and correctness were recorded automatically. The
participant then confirmed whether his response was correct and viewed the explanation in“explanation.” By repeating this process a few times, the participant learned the risk factors. In
this study, the iPad (Apple, MD328J/A) was used to present the images and obtain the data
(Cyvision, Ltd., 2013).
Four types of work (work on scaffolding, work with a stepladder, work with a circular saw,
and work with a nailer) in which work-related accidents frequently occur at residential
construction sites were selected as the themes (The Japan Federation of Housing Organizations &National Institute of Occupational Safety and Health, Japan, 2010). Based on the opinions oflabor and safety supervisors for 14 housing manufacturers and the reproducibility of images,
eight risk factors were selected per type of work. Table 1 lists the selected risk factors.
One trial was created per risk factor, and eight trials were created per type of work, making
one set. In addition, two sets (A and B) were created for training and for verifying effectiveness.
Cast, clothes, work location, and angle were changed in order to change the impression of thesame risk factors in sets A and B. In addition, the set for training and the set for verifying
effectiveness were not decided, and participants were randomly assigned to these sets.
Participants learned risk factors by repeating the training set three times. In order to determine
whether participants had learned the risk factors, they responded to the validation set. They
accomplished all four types of work. In addition, the presentation order of four types of work andeight trials, and the presentation positions of four images of the “question” were random. In thisstudy, 264 images (8 images for practice trials and 4 types of work × 8 trials × 2 sets) were taken
for the “question.” However, labor and safety supervisors in 14 housing manufacturers
determined that an image of the risk factor of “A worker climbs a stepladder while having thingsin both hands” was inadequate. Therefore, work with a stepladder was one set of seven trials.

Indicator of safety training effectivenessIn studies on safety education in the field of traffic psychology, various indicators have been used
to determine the effectiveness of safety training. The first is understanding of the educational
content (Shimazaki et al., 2012). The second is the transformation of attitudes through education,
so that participants’ attitudes (e.g., behavior and self-evaluation) change to the safe side (Renge
& Kokufuda, 2003; Ohtani et al., 2011). The third is the duration of the effectiveness (i.e.,
whether the effectiveness is ongoing for a few months) (Ota et al., 2007; Dommes et al., 2011).

Work situation

Question

Touch!

A screen of tablet PC

Figure 1. Training with the safety-training tool

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Explanation

Table 1. Risk factors

Work
Work on scaffolds surrounding

Risk factors
1 . A worker is not using the safety belt where the scaffolding and the building frame is away.
2 . Handrail of the scaffolding is removed and left.
3 . When a worker is working, there is a point where the work floor is removed.
4 . A worker moves up and down without lifting equipment.
5 . A material is left in the scaffold.
6 . A worker is working while putting a foot on the handrail.
7 . A worker is working without putting a stopper near the step.
8 . A worker is working while putting a safety belt near his foot.

Work with a stepladder

1 . Stepladder is deformed.
2 . A stay to prevent opening is not used.
3 . A worker climbs a stepladder while having things in both hands.
4 . A worker is working while riding on the top plate.
5 . A worker is working with unreasonable posture on a stepladder.
6 . A worker is working on a stepladder where things are messy.
7 . A worker is working on a stepladder on the step.
8 . A worker get off the stepladder while his back turning to it.

Work with a circular saw

1 . A worker checking out the circular saw that is pluged in before work.
2 . A worker is using the circular saw while fixing the safety cover.
3 . A worker is using the circular saw with a towel hanging from the neck.
4 . A worker is using a circular saw with work gloves
5 . A worker is using a circular saw while holding the material.
6 . A worker is using a circular saw when things are messy on the platform .
7 . Position of the body is not away from the extension of the blade.
8 . A worker leaves a circular saw pluged in after work.

Work with a nailer

1 . A worker checking out the nailer that the air hose is connected with before work.
2 . A worker leaves a circular saw pluged in after work.
3 . A worker does not wear protective eyewear during work.
4 . A worker moves the room while the air hose being connected with the nailer.
5 . A worker's finger was left hanged on the nailer
6 . There are people in the direction a worker hits the nail7 . The muzzle of the nailer was turned toward another worker.
8 . A worker leaves the air hose connected with the nailer after work.

In this study, understanding of educational content was used as an indicator. Results of thefirst task and the fourth task were compared to determine whether the percentage of correct
answers increased, and whether the time required to judge dangerous situations decreased.

Participants

The participants in this study were 70 male construction workers (carpenters or siding craftsmen)
who worked for subcontractors of housing manufacturers. A worker used glasses if he had vision
problems. In order to consider whether the tool’s effectiveness differed by age, participants weredivided into three groups: young, middle-aged, and older. There were 17 men in the young group(age 23 to 35, [mean, SD] 29.8±4.0), 36 men in the middle-age group (age 36 to 50, [mean, SD]
41.6±4.2), and 17 men in the older group (age 51 to 73, [mean, SD] 60.9±5.9).

Procedure

The experiment content and method of operation of the safety-training tool were explained to theparticipants, who then signed an informed consent form. At this time, participants were told thatthey could discontinue the experiment if necessary. The simple reaction time was then measured(5 practice trials and 20 test trials). Simple reaction time was measured as follows. A black
screen was presented on the tablet PC for a few seconds, and then a white screen was presented.
Participants were instructed to touch the white screen as quickly as possible. The time from thepresentation of the white screen to the participant’s touching the screen was defined as the simple
reaction time. Furthermore, the white screen was randomly presented at intervals of 3 to 7
seconds. The participants then received training using the safety-training tool (2 practice trials
and 124 test trials). At this time, participants were instructed to touch the dangerous images as
quickly as possible.

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Result
Comparison of the percentages of correct answers

Figure 2 compares the percentages of correct answers by age. A 3 age × 2 times (1st time,
4th time) ANOVA was conducted on the percentage of correct answers. A significant main
effect with age and times was observed for work on scaffolding and work with a nailer (WORKON SCAFFOLDING age F(1,67) = 16.32, p<0.001; times F(2,67) = 11.98, p<0.001; WORKWITH A NAILER age F(1,67) = 14.77, p<0.001; times F(2,67) = 4.65, p<0.05). For work witha stepladder and work with a circular saw, a significant interaction between age and times wasobserved (WORK WITH A STEPLADDER F(2,67) = 4.19, p<0.05; WORK WITH A
CIRCULAR SAW F(2,67) = 3.14, p<0.05). Results of the post hoc test indicated that for work in
scaffolding and work with a nailer, the percentage of correct answers of all age groups increased
from the first time to the fourth time (all combinations p<0.001). For work with a stepladder, thepercentage of correct answers of the older group increased from the first time to the fourth time
(p<0.001); and for work with a circular saw, the percentage of correct answers of the younggroup and the middle-aged group increased from the first time to the fourth time (young groupp<0.001; middle-aged group p<0.05). Therefore, the percentage of correct answers of most age
groups in all types of work significantly increased from the first time to the fourth time.
In addition, comparison by age indicated that for work on scaffolding, the percentage ofcorrect answers of the older group was lower than those of the other two groups (young and older
p<0.001; middle-aged and older p<0.001); and for work with a nailer, the percentage of correct
answers of the older group was lower than that of the young group (p<0.05). For work with acircular saw, the first-time percentage of correct answers of the older group was lower than thatof the middle-aged group (p<0.05), and the fourth-time percentage of correct answers of theolder group was lower than those of the other two groups (young and older p<0.05; middle-aged
and older p<0.01). For work with a stepladder, the first-time percentage of correct answers of theolder group was lower than those of the other two groups (young and older p<0.05; middle-aged
and older p<0.05). However, the fourth-time percentage of correct answers of the older group did
not differ from those of the other two groups. Therefore, the first-time percentage of correct
answers of the older group was significantly lower than those of the other two groups, and thefourth-time percentage of correct answers of the older group did not increase to the level of theother two groups, except for work with a stepladder.

Comparison of the time required to judge dangerous situations

A participant was presented with a black tablet screen and told to touch a white screen assoon as it appeared. The required time was defined as the simple reaction time. After several
iterations of this, the participant was presented with a screen containing four images and was told
to touch the image depicting a dangerous situation as quickly as possible. The required time wasthen defined as the reaction time. The simple reaction time was then subtracted from the reaction
time to obtain the judgment time. In addition, wrong answers were excluded from the data.
Figure 3 compares the time required to judge dangerous situations by age. A 3 age × 2 times(1st time, 4th time) ANOVA was conducted on the time required to judge dangerous situations.
For all types of work, the significant main effect with age and time was observed (WORK ON
SCAFFOLDING age F(1,67)=77.65, p<0.001; time F(2,67) = 4.29, p<0.05; WORK WITH A
STEPLADDER age F(1,67) = 120.08, p<0.001, time: F(2,67) = 16.05, p<0.001; WORK WITH
A CIRCULAR SAW age F(1,67) = 134.32, p<0.001; time F(2,67) = 3.96, p<0.05); WORKWITH A NAILER age F(1,67) = 47.04, p<0.001; time F(2,67) = 14.22, p<0.001). Results of thepost hoc test indicated that for all types of work and for all age groups, the time required to judge
dangerous situations decreased from the first time to the fourth time (all combinations p<0.001).
For work on scaffolding, the middle-aged and the older groups’ judgment times were longer thanthat of the young group (p<0.05). For work with a stepladder, the older group’s judgment time
was longer than those of the young group and the middle-aged group (p<0.001). For work with acircular saw, the older group’s judgment time was longer than that of the young group. For workwith a nailer, the older group’s judgment time was longer than those of the young group and the- 148 -

middle-aged group, and the middle-aged group’s judgment time was longer that of than theyoung group.

Discussion
Effectiveness in understanding educational content

The percentage of correct answers of all age groups significantly increased for work on
scaffolding and work with a nailer. The percentage of correct answers of the older group
significantly increased for work with a stepladder. The percentage of correct answers of theyoung group and the middle-aged group significantly increased for work with a circular saw.
Furthermore, the time required for all groups to judge dangerous situations decreased. Since
different images with the same risk factors were presented between the first time and the fourthtime, this result suggests that all groups came to understand the dangers and focused on themmore quickly, and that the tool was effective in facilitating comprehension of curriculum content.
The percentage of correct answers of the young group and the middle-aged group did not
significantly increase for work with a stepladder. Since the first percentage of correct answers of
the young group and the middle-aged group was near 1, this result may be due to the ceiling
effect. In addition, the percentage of correct answers of the older group did not significantly
increase for work with a circular saw. This result suggests that only three repetitions of training
are insufficient for the older group.
Comparison of effectiveness among three age groups
In general, older people are not familiar with information equipment. However, the data in thisstudy were obtained by the very simple reaction of a worker who selects one of four images.
Therefore, the effect of familiarity with information equipment was considered to be low. Basedon this assumption, we consider a comparison among age groups.
The first percentage of correct answers for the older group was lower than those of the two

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the percentage of correct answers***

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the percentage of correct answers

1.2

the percentage of correct answers

the percentage of correct answers

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1.2

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middleaged

older

1.0
0.8
0.6
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Figure 2. Comparison of the percentage of correct answers of each work group by age
1st time

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3rd time

the time required to judge
dangerous situations(sec)

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2nd time*

the time required to judge
dangerous situations(sec)

20.0

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the time required to judge
dangerous situations(sec)the time required to judge
dangerous situations(sec)

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middleaged

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Figure 3. Comparison of the time required to judge dangerous situations for each workgroup by age- 149 -

other groups for all types of work. Since the older group was likely to have long experience andknowledge about safety, this result was contrary to what was expected.
The percentage of correct answers of the older group did not increase to the same level as
those of the other two groups, except for work with a stepladder. This result suggests that only
three repetitions of training are insufficient for the older group. However, some participants werereluctant to perform the same set repeatedly. Therefore, it is necessary to consider alternative
strategies, such as reducing difficulty by a simple image of the “question.”

Conclusions
This study sought to create a tablet-PC-based safety-training tool for residential construction
workers and to compare this tool’s effectiveness by age. The percentage of correct answers of allgroups increased. Furthermore, the time required for all groups to judge dangerous situations
decreased, suggesting that all groups came to understand the dangers and focused on them more
quickly, and that the tool was effective in facilitating comprehension of curriculum content.
However, the tool was less effective for the older group than for the other two groups, suggesting
the need to improve the tool for older workers.

Acknowledgments
The authors appreciate the assistance of the members of the subcommittee of construction CS
labor safety management in the Japan Federation of Housing Organizations.

References
Cyvision, Ltd. (2013). Hazard Touch. Retrieved June 28, 2013, from https://itunes.apple.com/jp/
app/hazardtouch/id539416327
Dommes, A., Cavallo, V., Vienne, F. , Aillerie, I. (2012). Age-related differences in streetcrossing safety before and after training of older pedestrians. Accident Analysis andPrevention, 44, 42-47
Ohtani, A., Hashimoto, H., Okada, K., Okano, R. & Kobayashi, T. (2011). Applicability of
Repeated Traffic Safety Education with Group Discussion and Role Playing Methods̾
Traffic Safety Education for Upper Grade Elementary School Students̾ , JARI Research
Journal, 33, 37-40, in JapaneseOta, H., Nakanishi, M. & Kato, Y. (2007). Using Driving Simulators in Safety Training forYoung Drivers: Developing an Educational Program through the Application of Coaching
Techniques. IATSS Review, 32. 317-326, in JapaneseRenge, K. & Kokufuda, M. (2003). Evaluative Study of Educational Traffic Safety Program“AYATORI” for Primary School Children. Japanese Journal of Applied Psychology, 28,
100-111, in Japanese
Shimazaki, K., Mishina, M., Nakamura, A., Takahashi, A. & Ishida, T. (2012). Driver Education
Using a Tablet Device and Movies of Accidents Recorded by Drive Recorders. Japanese
Journal of Traffic Psychology, 28, 35-43, in Japanese
The Japan Federation of Housing Organizations & National Institute of Occupational Safety and
Health, Japan. (2010). Guide book for preventing human errors for residential construction
sites, in Japanese- 150 -