Journal of Software Engineering and Applications, 2013, 6, 1-4
http://dx.doi.org/10.4236/jsea.2013.610A001 Published Online October 2013 (http://www.scirp.org/journal/jsea)
Copyright © 2013 SciRes. JSEA
1
Towards Specifications for Automatic Recognition
Software: An Example of a User-Centred Design
Sylvain Fleury1*, Éric Jamet1, Emilie Loup-Escande1, Achraf Ghorbel2, Aurélie Lemaî tre2,
Eric Anquetil2
1Centre de Recherche en Psychologie, Cognition et Communication (CRPCC), University of Rennes 2, Rennes, France; 2Institut de
Recherche en Informatique et Systèmes Aléatoires (IRISA), INSA Campus de Beaulieu, Rennes, France.
Email: *sylvain.fleury@uhb.fr
Received August 8th, 2013; revised August 30th, 2013; accepted September 5th, 2013
Copyright © 2013 Sylvain Fleury et al. This is an open access article distributed under the Creative Commons Attribution
License, which permits unrestricted us e, distribu tion, and reproduction in any medium, provided th e or i g in a l w or k i s pr o pe rl y cited.
ABSTRACT
This article describes a user-centred method used to design innovative pattern recognition software for technical paper
documents. This kind of software can make some errors of interpretation. It will therefore be important that human op-
erators are able to identify and correct these mistakes. The identification of errors is a difficult task because operators
need to establish co -reference between the initial document and it in terpretation. Moreover, users must be able to checks
the interpretation without forgetting any area. This task requires the interface is easy to use. The experiments showed
that the sequential display o f interpretation is the most effective and that the interru ptions by user reduce task duration.
Moreover, queries by the system may improve error detection. This paper summarizes the main results of the research
conducted in the context of this design for enhance the interface, and describes the specifications to which it gave rise.
Keywords: User-Centred Design; Interpretation of Document; Error Detection
1. Introduction
There are currently several fields of application for pat-
tern recognition software. For example, it can be used to
recognize logic circuit diagrams, engineering drawings,
maps, musical scores, architectural drawings and logos
[1]. The automatic recognition of technical paper docu-
ments produces digital interpretations that are directly
compatible with dedicated software. In this article, we
describe a user-centred method we used to design inno-
vative software that is capable of automatically inter-
preting hand-drawn architectural floor plans1. With this
kind of interpretation software, there is always a risk of
making mistakes. For instance, preliminary tests of our
software revealed an error rate of 9% for simple plans [2].
It is therefore important for users to be able to identify
these mistakes.
2. User-Centred Design
Two complementary approaches have been adopted in
software design: a technocentric approach and an an-
thropocentric approach. The aim of the former is to de-
sign and optimize innovative software by testing its
technological possibilities and resolving technical glitch-
es. The aim of the latter is to design software that is
adapted and adaptable to its end-users [3]. Ergonomics
takes the anthropocentric approach, relying on human-
centred design. The ISO 9241-210 [4 ] standard identifies
six principles that characterize human-centred design: 1)
the design is based upon an explicit understanding of
users, tasks and environments; 2) users are involved
throughout design and development; 3) the design is dri-
ven and refined by user-centred evaluation; 4) the proc-
ess is iterative; 5) the design addresses the whole user
experience; 6) the design team includes multidiscip linary
skills and perspectives. The application of these princi-
ples gives rise to four main tasks. The first task consists
in understanding and specifying the context of use. The
second in specifying user needs and the other stake-
holders’ requirements, the third task in producing design
solutions (e.g. scenario, mock-up, prototype), and the
fourth task in assessing the solutions at each stage in the
project, from the early concept design to long-term usage,
in order to make the right design choices. There are two
*Corresponding a uthor.
1This project, named “Mobisketch”, is funded by the French National
Research Agency (ANR). Its reference is 09-CORD-015 (http://mo-
bisketch.irisa.fr).
Towards Specifications for Automatic Recognition Software: An Example of a User-Centred Design
Copyright © 2013 SciRes. JSEA
2
main user-centred methods that can be used to carry out
this fourth task, namely user-based testing and expert
evaluation based on the usability literatu re. In our proj ect,
we opted for a combination of user-based testing and
usability heuristics. These evaluation methods are com-
plementary, as experimental user testing yields informa-
tion about user behavior in a specific interaction with a
designed solution, while the usability literature provides
general knowledge about the human characteristics that
need to be integrated in an interface. Together, these two
evaluation methods would help us come up with precise
specifications for designing software capable of auto-
matically recognizing architectural plans. In the follow-
ing sections, we summarize the main results of our re-
search and describe the specifications to which it gave
rise.
In a preliminary test, we asked 40 volunteers to check
for errors of interpretation made by our initial prototype.
The two pictures that had to be compared (the hand-
drawn plan and its interpretation) were displayed side by
side. In this seemingly simple task, only 33% of the vol-
unteers succeeded in identifying all the errors. The speci-
fications described below came out of a series of studies
conducted during the user-centred design phase. They
apply to the design of all automatic recognition or beau-
tification software.
3. How Can We Facilitate Plan
Comparisons?
Thirty-six participants were divided into two groups.
They were told to circle the errors in three interpretation s
of three plans. For the first group, the plans and their
interpretations were displayed side by side, whereas the
second group worked on interpretations that were su-
perimposed on the plans (see Figure 1).
Results failed to reveal any significant difference be-
tween the two groups in the accuracy of pinpointing er-
rors. However, it took the participants who had to com-
pare two separate images significantly lo nger to complete
the task than those whose images were superimposed.
This result is consisten t with the principle of spatial con-
tiguity, according to which distant visual information
sources hinder learning [5]. Although our task involved
error searching, rather than learning, this principle can
still be used to explain our results. When the plan was
separated from its interpretation, the participants had to
store informati on from the plan, such as the lo cation of a
door, in working memory and find the equivalent loca-
tion in the interpretation. This sort of visual searching is
costly in cognitive resources and a waste of time for us-
ers. Superimposing the interpretation produced by the
software on top of the original source reduces the visual
searching and enables users to save time.
Figure 1. A plan and its interpretation displayed side by
side (top) or superimposed (bottom).
4. How Can We Facilitate Error Detection?
A third group of 18 volunteers took part in a similar
study, in which the interpretation gradually appeared on
the screen, as and when each feature was recognized by
the software. Results showed that the realtime display of
the interpretation significantly improved the percentage
of participants who spotted all the errors. The sudden
appearance of an item on the screen triggers attentional
capture [6]. In all prob ability, th e sequential n ature of the
display meant that all the participants checked all the
areas of the plan in turn, whereas had the interpretation
appeared all of a sudden, they might have forgotten to
check some of them. A replication of this study, supple-
mented with eye movement recordings, corroborated this
interpretation of the results.
To assess the need for visual cueing, we conducted in-
terviews with 18 participants after they had used the
prototype. Many of them complained that the symbols
did not appear on the screen in a logical order. For ex-
ample, the software might interpret three symbols that
were close together, then one that was located on the
other side of the plan. Depending on the software’s tech-
nical characteristics, it is sometimes not possib le to mod-
ify the order of symbol recognition. When there is no
obvious logic to this order, the software can implement a
pre-guiding function, whereby the feature it is about to
process is highlighted with a colour halo (see Figure 2).
This attentional focus tells th e user which symbol will be
interpreted next.
This addition is consistent with the heuristic criterion
Towards Specifications for Automatic Recognition Software: An Example of a User-Centred Design
Copyright © 2013 SciRes. JSEA
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Figure 2. Visual cue indicating which symbol will be proc-
essed next.
of Molich and Nielsen [7], known as the “visibility of
system status”, which consists in showing the user what
the software is doing. We also applied the “match be-
tween system and real world” criterion, by using intuitive
colors for the symbol interpretations. For example, we
avoided using red, which could be interpreted as flagging
up an error, and green, which could be interpreted as
signalling a correct interpretatio n.
5. How Can We Facilitate Error Correction?
Once users have pinpointed errors, they then have to
memorize them until they reach the end of the process.
However, the gradual forgetting of visual patterns is am-
plified when a visual distractor prevents rehearsal [8].
We asked 36 volunteers to check the outcome of an
automatic recognition process and circle any errors they
found. Half of them could interrupt the recognition proc-
ess and circle the errors as and when they spotted them
(see Figure 3). The other half had to wait until the end of
the process to do so.
Results showed that participants who interrupted the
system finished the task significantly more quickly than
the others. Participants who could not interrupt the sys-
tem ended up having to check the interpretation a second
time afterwards, because they had forgotten some of the
errors. Regarding the “provide shortcut” heuristic [7],
participants had two ways of correcting errors: an intui-
tive pause button at the top of the screen and a direct
click on the error (invisib le to novices).
6. Can the System Support Users?
We assessed the functionality whereby the software asks
the user for help whenever a symbol proves difficult to
interpret. Forty-eight participan ts were asked to sup erv ise
the automatic recognition of plans. For twenty-four of
them, the software might stop at any time to ask the user
if the most recent interpretation was relevant or not (see
Figure 4). If not, it proposed possible corrections. The
other twenty-four participants were not asked for their
input.
Results showed that this type of questioning can save
time, and errors signalled in this way are more likely to
be corrected. However, we must be careful with this
functionality, as there is a risk that users may relax their
vigilance.
Figure 3. Participant circling an error before the end of the
automatic recognition process.
Figure 4. The system asks the user for help.
Towards Specifications for Automatic Recognition Software: An Example of a User-Centred Design
Copyright © 2013 SciRes. JSEA
4
7. From Technocentric Design to
User-Centred Design
Results showed how an anthropocentric approach based
on user-centred design, consisting of experimental tests
and usability heuristics, makes it possible to specify the
functions and properties of automatic recognition soft-
ware. At the end of the technological design process, just
33% of users corrected all the errors contained in simple
plans (i.e. 15 symbols), whereas at the end of anthropo-
centric design process, 75% of users corrected all the
errors contained in complex plans (i.e. 60 symbols).
In future works, requests to users must be evaluated
more precisely. The benefit of this type of assistance
seems to be largely dependent upon its accuracy. Conse-
quently, several degree of accuracy must be tested in
further experiments.
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