This document summarizes a study that identified and evaluated usability heuristics applicable to clinical laboratory systems. The researchers assembled a set of existing heuristics and integrated them with Nielsen's 10 general heuristics. They validated the combined heuristics set by comparing heuristic evaluations of an existing clinical laboratory system and a prototype system designed with the heuristics. The prototype performed better, with users completing tasks faster and making fewer errors. This demonstrated that following usability heuristics can improve clinical laboratory systems.

1. João Marcus Alves1,2
, Christiane Gresse von Wangenheim1,2
, Alexandre Savaris², Aldo von Wangenheim1,2
1
Federal University of Santa Catarina (UFSC) – Dept. of Informatics and Statistics – Florianópolis – SC – Brazil
2
National Institute for Digital Convergence (INCoD) – Florianópolis – SC – Brazil
joao@telemedicina.ufsc.br ,gresse@inf.ufsc.br, savaris@telemedicina.ufsc.br, awangenh@inf.ufsc.br
Identifying and Evaluating Usability Heuristics Applicable to
Clinical Laboratory Systems
LABTELEMED – Laboratório de
Telemedicina e Informática Médica
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www.telemedicina.ufsc.br
Introduction
Clinical Laboratory Systems (CLSs) are projected, built,
and deployed to organize the workflow of a clinical
laboratory in executing clinical examinations, aiming to
reduce operational errors, tracking personnel workload,
and monitor patients’ condition.
To ensure a proper management of the laboratory
workflow, as well as the reliability of the resulting data,
usability is a mandatory aspect to be observed in
assuring the overall quality of a CLS.
Heuristics Unification and Evaluation
A set of state-of-the-art heuristics regarding CLSs was
assembled and harmonized with the classical set of
Nielsen’s 10 heuristics [1], a general serving and strong
core for the CLS heuristics set. In this harmonization,
the concepts of eight unified heuristics could be
incorporated to the Nielsen heuristics. The following
three heuristics could not be harmonized:
In executing critical activities, time must be
visible – In critical activities the time must be always
easily visible to the user. The system also must show
an appropriated alert in case of an uncommon result.
Information detailing – The system must be
compatible with a high level detailing for the registered
information. However, the detailed information must not
be required.
Mapping vocabularies – To map the medical
vocabulary in a way that it is understandable to all
users, preferentially using a standard vocabulary such
as SNOMED (Systematized Nomenclature of
Medicine).
Errors perceived in the LACEN system for the first and third
steps did not occur in the prototype, and for the fourth step
errors were reduced in approximately a half. The only
drawback occurred in the execution of the second step,
where the LACEN system performed better. A comparison
between the LACEN system and the prototype can be seen
in Fig. 2.
Grupo Cyclops
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[1] J. Nielsen. “Heuristic evaluation” in J. Nielsen & R.
L. Mack (Eds.), Usability
References
1st Step: Register the 1st sample
2nd Step: Register the 2nd sample
3rd Step: Retain the sample
4th Step: Sorting the sample
1st Step: Register the 1st sample
2nd Setp: Register the 2nd sample
3rd Step: Retain the sample
4th Step: Sorting the sample
LACEN
SLC
00:00 00:20 00:40 01:00 01:20 01:40 02:00 02:20 02:40
0.00 0.20 0.40 0.60 0.80 1.00 1.20 1.40
Average Time Average Number of Errors
Average Task Time (mm:ss)
Task
Average Number of Errors
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Results and Discussion
The resulting set of heuristics has been refined into a
checklist in order to guide its evaluation. It was
validated through a case study comparing results of a
heuristic evaluation with a usability test of two systems,
a CLS used by the Central Laboratory of Public Health
(LACEN) in Santa Catarina, Brazil, and a high-fidelity
CLS prototype. The results of the heuristic evaluation
can be seen in Fig. 1.
The high-fidelity prototype presented the best results
(i.e., more questions answered positively), indicating
the adoption of a larger set of heuristics when
compared to the clinical laboratory system used by
LACEN.
Considering the time needed to register a sample, the
high-fidelity prototype outperformed the LACEN system.
Contributing to reduce the time needed to register a first
sample in 64.6%, and to an overall reduction of 47.6%
in execution time for the whole task, the adoption of the
unified heuristic set proved its viability, allowing users to
perform the same steps in a faster way.
The high-fidelity prototype presented, also, a
reduction in the error rate on executing the chosen task.
64%
34%
2%
LACEN CLS
# Yes # No # N/A
71%
24%
6%
CLS Prototype
# Yes # No # N/A
Fig. 1 – Results of the heuristic evaluation.
Fig. 2 – Results of the heuristic test.
Conclusion
This work proposes a set of usability heuristics customized
to clinical laboratory systems, and evaluates its applicability
through a heuristic evaluation and a usability test. The
proposed set is derived from a deep theoretical reasoning
in the fields of Human-Computer Interaction (HCI), usability
and CLSs, and gathers the state-of-the-art in heuristics for
such systems.
In applying the heuristics set to build a high-fidelity
prototype, results attest the effectiveness of the
proposal when compared to a CLS system already in
use. Being faster and less error-prone, the prototype is
an example of the advantages in adopting an
engineering life-cycle including usability heuristic
guidelines.
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DE SANTA CATARINA
www.ufsc.br