International Journal
on Marine Navigation
and Safety of Sea Transportation
Volume 4
Number 1
March 2010
73
1 INTRODUCTION
A decrease in crew performance for maritime works
can be caused by the complex causation related to
physiological, psychological, and external sailing
factors (Kim et al., 2004). A procedure in maritime
accidents caused by the reduction of crew perfor-
mance can be explained as follows. Physiological,
psychological, and external sailing factors affect the
working process of a marine pilot directly or indi-
rectly. These factors decrease physical and psycho-
logical abilities and that ultimately affect decreases
in the cognitive performance of crews as ultimate
factors. The decrease in cognitive performance caus-
es mistakes, such as negligence of lookout, and that
lead to a direct cause of accidents.
As shown in Figure 1, human cognitive perfor-
mance represents all abilities of the elements pre-
sented in an information processing model of human
(Wickens, 1992). However, it may not be necessary
to measure the all abilities of such cognitive ele-
ments in a project that investigates the cognitive per-
formance of a worker who processes given works. In
general, there exist cognitive elements to play a de-
finitive role in the effective performance for given
cognitive works. Because these elements are enough
to perform such given works except for a decrease in
cognitive performance caused by certain diseases, it
is possible to estimate the cognitive performance of
a worker in given works using such definitive ele-
ments in the cognitive works.
Figure 1. Model of human information processing
Subjective methods, physiological monitoring,
and task loading methods are generally used to eval-
uate these cognitive performances. Also, these
methods have been applied to some high risk indus-
tries, such as national defense, road transportation,
railways, aerospace, process control, and power gen-
eration in which the selection of a method usually
depends on specific requirements related to each in-
dustry.
A representative study in subjective methods is
the Modified Cooper-Harper Scale (MCH) (Wier-
wille and Casalli, 1983) that complemented the
Collision Scenario-based Cognitive
Performance Assessment for Marine Officers
H. Kim & H.-J. Kim
Marine Transportation & Pollution Response Research Dept., MOERI/KORDI, Daejeon,
Korea
S. Hong
Chungju National University, Chungju, Korea
ABSTRACT: The overall aim of this paper is to determine a fatigue factor that can be applied to human per-
formance data as a part of a software program that calculates total cognitive performance. This program ena-
bles us to establish the levels of cognitive performance in a group of marine pilots in order to test a decision-
making task based on radar information. This paper addresses one of the factors that may contribute to the de-
termination of various fatigue factors: the effects of different work patterns on the cognitive performance of a
marine pilot.
74
Cooper-Harper Scale, which was developed to eval-
uate the performance of the handling characteristics
of military aircrafts in the end of the 1960s. In addi-
tion, the NASA TLX (Hart and Staveland, 1988) is a
biploar-rating scale-based study using self-report
scores.
In the case of the physiological monitoring, there
are some studies on the variation of human physiol-
ogy responses, such as Electroencephalogram
(EEG), Electrocardiogram (ECG), Electrodermal ac-
tivity (EDA), and Electrooculogram (EOG), accord-
ing to task demands (Andreassi, 2000).
The task loading methods represent an engineer-
ing approach that is to measure workloads based on
the estimation of task demands. The Task Analysis
Workload (TAWL) Methodology (Mitchell, 2000)
that was developed by using the US Army Light
Helicopter Experimental Program and the Operator
Function Model-Cognitive Task Analysis (OFM-
COG) (Lee and Sanquist, 2000) that was developed
to evaluate workloads in ship-borne automation sys-
tems applied these methods.
Marine officers perform various cognitive works,
such as signal detection, situation recognition, gen-
eral judgment, and other related works, in their ship
operation jobs. For instance, it can be considered as
perceptual ability to recognize target ships ap-
proached to their own ship through radars and the
naked eye, memory ability in a steersman who
memories the commands from his captain, and
judgment ability to determine the scale of the con-
version (heading) of the bow to avoid the collision
with approached target ships. It is difficult to guar-
antee that such cognitive works occur intermittently
or sequentially. Requirements in excessive cognitive
performance may cause some mistakes in marine of-
ficers and that lead to maritime accidents (Lee,
2005). However, there are still limited studies on the
quantitative evaluation of the cognitive performance
for maritime officers.
Thus this study developed a maritime collision
scenario-based cognitive performance evaluation
system for marine officers. The evaluation criteria
was configured by applying practical experiments
for a group of marine pilots and verified the system
through practical applications for cadet marine pi-
lots. Because this system is able to evaluate general
cognitive performance of marine officers, it is able
to play a role in the avoidance of accidents based on
their own awareness on such accidents by transfer-
ring the results of the evaluation of physical and
psychological conditions through applying a test for
a short period of time before going on duty or board-
ing.
2 COLLISION SCENARIO-BASED COGNITIVE
PERFORMANCE ASSESSMENT
In this study, we developed a computer program to
evaluate the abilities of signal detection and deci-
sion-making task in cognitive performance for ma-
rine officers. The objective of this program is to
measure the perceptual ability (signal detection) of
marine officers for searching other ships through the
information presented on radars and the judgment
ability (situation recognition or decision-making)
that determines the direction and speed of a ship to
avoid the collision with other ships. The cognitive
performance evaluation program for marine officers
developed in this study reflects general cognitive
abilities for operating a ship and measures the per-
formance through a 10 minute simple test before go-
ing on duty or boarding.
Also, this system is a program that measures the
cognitive performance of a marine pilot who con-
trols the heading and speed of a ship using the in-
formation presented in a ship operation process. In
general, the information given to marine officers is
the data presented on radars and speed information
of their own ship. The marine officers possibly ob-
serve a planned course and control the heading and
speed of their own ship in order to avoid the colli-
sion with other ships. After avoiding possible colli-
sion, the marine officers should return its own
course.
Figure 2. Screen of an evaluation of cognitive performance
Figure 2 illustrates a screen image of the cogni-
tive performance evaluation. The left side of the
screen represents the information of target ships
(DCPA, TCPA, Heading, Speed, Bearing, and
Range) and the right side shows the input menu of
the information for changing a course. Whereas, the
DCPA (Distance at Closest Point of Approach)
shows the estimated distance to the recent closest
point and the TCPA (Time to Closest Point of Ap-
proach) demonstrates the estimated time to the re-
cent closest point. In order to attempt a proper action
75
for collision avoidance, it is necessary to input the
action time for collision avoidance, heading and
speed at the starting point, termination time for colli-
sion avoidance, and heading and speed at the termi-
nation point.
This system configured 10 collision scenarios as
noted in Table 1 by varying the number of target
ships, heading and speed, and bearing based on the
four rules presented in the International Regulations
for Preventing Collisions at Sea (1972).
Table 1. Types of scenarios
Although the Scenarios 1 and 3 show the same
situation, “Head-on Situation”, target ships represent
different headings and speeds. The Scenarios 2 and 5
show the same situation, “Crossing Situation”, but
they represent different numbers of target ships,
such as one and two ships. Also, the Scenarios 4 and
6 show the same situation, “Overtaking”, but they
demonstrate different headings and speeds.
This system configured a scoring index to evalu-
ate the cognitive performance of marine officers as
follows.
1 Collision avoidance ability
2 Decision-making time
3 Degree of deviation
The evaluation criteria were produced for each
scenario with advice from professional marine pi-
lots. They were not participated in the experiments.
Table 2 shows the evaluation criteria for “Crossing
Situation”.
3 EXPERIMENTS & RESULTS
Three professional marine pilots and five cadet ma-
rine pilots were participated to verify the evaluation
of the cognitive performance assessment system for
marine officers developed in this study. Except for
Scenario 1, which was applied as a pretest, experi-
ments were applied to other nine Scenarios.
Figure 3 shows a screen image of the collision
scenario of “Traffic Separate Schemes". An experi-
ment based on this scenario represents the input and
analysis data as shown in Figure 4.
Table 2. Evaluation criteria for “Rule 15 "