5.4.1.1. Hazard identifification. VR technology acts as an experience

oriented method of safety hazards cognitive for difffferent construction

participants in various project/activity/work-task levels. The multiple

baseline testing was adopted by Albert et al.[42]which selected six

baselines based on occupations (mechanical, civil, maintenance,

electrical, structural, and insulation) to conduct the experiment. It is

a method for validating the effffectiveness of workers in hazard

recognition. However, workers in various trades face difffferent types

of hazards. Thus, not all the hazards could be presented in this

experiment, which results in an inaccurate rate to hazard

identifification. The empirical records analysis is a subjective

evaluation method, which could be useful for a specifific project to

identify the hazards by designers and builders together[24]. This is a

new vision to involve the non-construction related participants (i.e.,

designers) to evaluate the VR in risk recognition and identifification. It

could be an effiffifficient way to reduce hidden hazards in the design phase.

5.4.1.2. Training and education. In the process of safety training, most

studies utilized the novice and professionals as the comparative subjects

through subjective (i.e., interview and questionnaire survey) and

objective (i.e., cognitive load, the level of satisfaction, completion

time) evaluation methods. As a matter of fact, most of the operatives or

workers deemed the safety problems were induced by the personal

behavior and attitude[60]. Although these platforms or systems can

assist operatives or workers in safety training, it is diffiffifficult to avoid the

occurrence of safety issues without the workers' commitment[86]. A

signifificant advantage was found for VR training for stone cladding work

and for cast-in-situ concrete work, but not for general site safety. VR

training was more e

ffffective in terms of maintaining trainees' attention

and concentration, as well as enhancing the trainees' con

fifidence[6,79].

In addition, trainees performed the walking tasks on real planks in an

X. Li et al.

Automation in Construction 86 (2018) 150–162

158immersed VR scaffffolding simulation with more caution, more realistic

responses (smaller stride length), less stress, and better stability with

than when they were on virtual planks only[72–74].

The standard practice to measure the effffectiveness of alternate

safety education methods is questionnaire surveys. Notably, students

showed optimistic attitudes towards using the game scoring as a way to

reflflect their safety knowledge[27]. Although questionnaire survey

could reveal a subjective measure of students' interest and engagement,

this is a secondary metric, and any new technology should be measured

by evaluating the degree of knowledge transfer[22]. The incorporation

of VR/AR technologies into pedagogical methods or modes should be

the development direction for construction safety education. Additional

works on easing the practice and studies are associated with VR/AR

content generation and reuse. This would allow individual instructors

to customize content tofifit their particular audience more effiffifficiently,

and update information in line with local best practices[27].

5.4.1.3. Inspection and instruction. Validation of safety inspection and

instruction include damage inspection[37], information retrieval and

safety reporting[35]. Some experiments show that it is feasible to

measure drift in damaged buildings as the objective indicators for

evaluating the accuracy of AR systems[52]. The effffectiveness of

retrieving building information was evaluated by comparing the

traditional 2D drawings and the AR systems. The results showed that

the mean completion times were signifificantly shorter for participants

using the AR systems, and the average success rates of participants

arriving at the correct answers were also signifificantly improved in on

site communication[39]. The potential of the proposed AR based

reporting system includes promptfifield reporting in 3D information,

minimizing the timefifield personnel spent on accessing project

information and communicating with others to resolve an issue/

conflflict on the job site[35].