A Typology of Temporal Data Imperfection
Nassira Achich
1
, Fatma Ghorbel
1,2
, Fayc¸al Hamdi
2
, Elisabeth Metais
2
and Faiez Gargouri
1
1
MIRACL Laboratory, University of Sfax, Tunisia
2
CEDRIC Laboratory, Conservatoire National des Arts et M
´
etiers (CNAM), France
Keywords: Data Imperfections, Typology of Temporal Data Imperfection, Direct and Indirect Imperfections, Natural
Language based Temporal Data, Context - Dependent Temporal Data.
Abstract:
Temporal data may be subject to several types of imperfection (e.g., uncertainty, imprecision..). In this context,
several typologies of data imperfections have been already proposed. However, these typologies cannot be
applied to temporal data because of the complexity of this type of data and the specificity that it contains.
Besides, to the best of our knowledge, there is no typology of temporal data imperfections. In this paper, we
propose a typology of temporal data imperfections. Our typology is divided into direct imperfections of both
numeric temporal data and natural language based temporal data, indirect imperfections that can be deduced
from the direct ones and granularity (i.e., context - dependent temporal data) which is related to several factors
that can interfer in specifying the imperfection type such as person’s profile and multiculturalism. We finish
by representing an example of imprecise temporal data in PersonLink ontology.
1 INTRODUCTION
Temporal data is an important aspect in representing
ontologies such as PersonLink (Herradi et al., 2015)
which is a multicultural and multilingual OWL 2 on-
tology for storing, modeling and reasoning on family
relations. However, temporal data are subject to var-
ious kinds of imperfection. For instance, we find ”I
lived in Berlin before changing my job”, ”I traveled
to Spain during 2005” and ”My sister married before
moving to Paris”. Several typologies of data imper-
fections have been proposed. Some are generic (e.g.,
typology proposed by (Bouchon-Meunier, 1993) )
and others are specific to some domains (e.g., typol-
ogy of imperfections adapted to the context of archae-
ological data proposed by (Desjardin et al., 2012) ).
However, to the best of our knowledge, there is no ty-
pology of temporal data imperfections. Temporal data
can have more imperfections compared to the ones
proposed in the generic typologies. Thus, these lat-
ters are inadequate to be adapted to temporal data.
In this paper, we propose a typology of tempo-
ral data imperfections. It is classified into direct im-
perfections of both numeric temporal data and natu-
ral language based temporal data, indirect imperfec-
tions that can be deduced from the direct ones and
granularity (i.e., context - dependent temporal data)
which is related to several factors such as person’s
profile and multiculturalism. The direct imperfections
can be deduced directly from the given data: uncer-
tainty, typing error, imprecision, missing and useless-
ness. The Indirect imperfections are those that can be
generated from the direct ones. We distinguish three
types of indirect imperfections: (i) The incoherence
can be generated from the uncertainty and typing er-
ror. (ii) The incompleteness can be generated from
the imprecision and the missing. (iii) The redundancy
can be generated from the uselessness. Granularity is
the general context of the given temporal data which
can determine the type of imperfection.
The rest of the paper is organized as follows. Re-
lated work is reviewed in the next section. Then, we
introduce our proposed typology of temporal data im-
perfections in Section 3. In Section 4, we represent
an example of imprecise temporal data in PersonLink
ontology. Section 5 summarizes our work and gives
some future directions.
2 RELATED WORK:
TYPOLOGIES OF DATA
IMPERFECTIONS
Related work about the typologies of data imperfec-
tions is discussed in this section. We distinguish two
Achich, N., Ghorbel, F., Hamdi, F., Metais, E. and Gargouri, F.
A Typology of Temporal Data Imperfection.
DOI: 10.5220/0008168403050311
In Proceedings of the 11th International Joint Conference on Knowledge Discovery, Knowledge Engineering and Knowledge Management (IC3K 2019), pages 305-311
ISBN: 978-989-758-382-7
Copyright
c
2019 by SCITEPRESS Science and Technology Publications, Lda. All rights reserved
305
types of typologies: generic typologies of data imper-
fections and specific typologies of data imperfections
in a given domain.
2.1 Generic Typologies of Data
Imperfections
We identify four generic typologies of data imperfec-
tions:
(Niskanen, 1989) proposes a typology of non-
precision of the data. He defines four concepts
which are uncertainty, imprecision, ambiguity and
generality. Uncertainty is a concept associated
with the accuracy and error definitions. Impre-
cision exists when objects are naturally imprecise
or the verbal expression can have several mean-
ings or when a human cannot identify an object
exactly. Ambiguity appears when there are sev-
eral points of view about the same subject of the
real world. Generality is the multiple representa-
tion of reality according to the level of detail.
(Bouchon-Meunier, 1993) in her first work dis-
tinguishes two types of imperfection which are
uncertainty and imprecision. In her second work
(Bouchon-Meunier, 1995), she distinguishes a
third factor of imperfection, which is the incom-
pleteness. She defines uncertainty by the validity
of the data. The imprecision of the data is due to
the vague or approximate nature of the used se-
mantic. Incompleteness is related to incomplete
data or lack of data.
(Klir and Yuan, 1995) propose a typology of
data uncertainty. The authors divide the uncer-
tainty into two classes which are fuzziness and
ambiguity. Ambiguity refers to conflict and non-
specificity.
(Smets, 1997) establishes a classification of the
imperfection of the data. It is divided into three
groups which are imprecision, inconsistency and
uncertainty. The imprecision is relative to the
content of the data that may or may not have er-
rors. Inconsistency is related to conflicting. Un-
certainty can be subjective (i.e. observer’s opin-
ion) or objective (i.e. data properties).
2.2 Specific Typologies of Data
Imperfections
We identify seven typologies of data imperfections
specific to a given domain.
(Gershon, 1998) focuses on kinds of imperfec-
tion in information that might be provided to an
analyst or decision maker. He proposes a taxon-
omy of causes for imperfect knowledge of the in-
formation state. The first level of the taxonomy
contains six inputs which are incomplete info,
inconsistency, info too complicated, uncertainty,
corrupt data/info and the quality of the presenta-
tion.
(Fisher, 2005) propose a typology of uncertainty
of geographic data. They classify the data into a
well or a badly defined data. In the case where the
data is well defined, it is subject to uncertainty. In
other cases, the data is poorly defined and the im-
perfection of the data is due to imprecision, ambi-
guity and / or incompleteness. He focuses on am-
biguity. It occurs when there is a doubt about how
to define an object or phenomenon. Two types of
ambiguities are recognized namely disagreement
and lack of specificity.
(Olteanu, 2006) propose a typology based on
(Fisher, 2003) and (Fisher, 2005) to classify the
imperfection of a set of textual data describing
ethnographic objects. Four types of imperfec-
tions are distinguished: Imprecision, uncertainty,
level of detail and incompleteness. Imprecision
concerns the difficulty of expressing knowledge
clearly and precisely. The uncertainty concerns a
doubt about the validity of information. The level
of detail is knowledge presented in several gran-
ularities. Incompleteness refers to the absence of
information.
(Casta, 2009) establishes a typology of the imper-
fection of the data resulting from the economic
activity. It is divided into uncertainty, impreci-
sion and error. Uncertainty refers to the state of an
agent who does not know about the future because
the set of possible events, or contingencies, in-
cludes more than one element and these elements
do not obey strict determinism. Imprecision refers
to a lack of rigor or an operational constraint that
affects measurement or, most often in the social
sciences, an ambiguity inherent in the formulation
of concepts. The error is defined as the dispersion
of probable gains and losses around their mean.
(Desjardin et al., 2012) rely on the typology of
(Fisher et al., 2005) to propose a typology of im-
perfection adapted to the context of archaeolog-
ical data. They classify imperfections into un-
certainty, imprecision, ambiguity and incomplete-
ness. The uncertainty occurs when there is a
doubt about the validity of knowledge. Impre-
cision is the difficulty in expressing knowledge
clearly. The ambiguity is the difficulty in agree-
ing. Incompleteness is the fact that there is miss-
KEOD 2019 - 11th International Conference on Knowledge Engineering and Ontology Development
306
ing or partial knowledge.
(M. Snoussi, 2014) propose a classification that
concerns a large set of imperfections that was built
specifically to characterize spatial data. This tax-
onomy distinguishes three types of imperfection:
Imprecision occurs when the true value is located
in a defined subset of values, inconsistency is the
conflict or incoherence in the values and uncer-
tainty is the partial knowledge about the true value
of information.
(Sta, 2016) proposes several types of imperfect
data during the process of information retrieval
and data integration in smart cities. This im-
perfection can have several forms: Uncertain in-
formation reflects the lack of knowledge, impre-
cision information translates the non-specificity,
vague information reflects an ambiguous infor-
mation and missing information reflects the not
found or incomplete information.
2.3 Discussion
There is a big number of typologies of data im-
perfection. Authors such as (Niskanen, 1989) and
(Bouchon-Meunier, 1995) start by proposing generic
typologies. Then, to respond to several domains, au-
thors such as (Fisher, 2005), (Desjardin et al., 2012)
and (Sta, 2016) propose typologies for specific fields.
However, some correspond better to a reality than
others. Also, there is not a definitive terminology
and definition of terms used to qualify imperfect data,
such as uncertainty and imprecision. We also note
that the majority of these typologies share three com-
mon concepts which are the imprecision, the uncer-
tainty and the incompleteness. Imperfection types
are interdependent. According to (Bouchon-Meunier,
1995), ”Incompleteness leads to uncertainties, im-
precision can also be associated with incomplete-
ness and they generate uncertainties during their han-
dling”. According to (Smets, 1998), imprecision al-
ways refers to incompleteness. Imprecision may be
the source of uncertainty, but not necessarily (Smets,
1998).
Temporal data can have more imperfections com-
pared to the ones proposed in the generic typologies
because of the complexity of this type of data and the
specificity that it contains (i.e., It can be numeric or
natural language-based. It can also depend on the
general context of the information that contains the
temporal data and they may also be subject to several
factors such as the multiculturalism). Thus, generic
typologies cannot be adapted to temporal data (i.e,
they are inadequate). For instance, if we have the in-
formation ”I forget when last time I visited my uncle
who lives in Japan ”, the temporal data indicates a
”Missing” which is a type of imperfection that no one
of the generic typologies contains. Another example
is ”The first day of the week, we will have a meeting”.
In this example the temporal data indicates a ”circum-
locution” which is another type of imperfection that
no one of the generic typologies contains. Finally, to
the best of our knowledge, there is no typologies ded-
icated to temporal data imperfection.
3 OUR TYPOLOGY OF
TEMPORAL DATA
IMPERFECTION
In this section, we introduce our typology of tempo-
ral data imperfections illustrated by Figure 1 . Our
typology is based on the studied mentioned typolo-
gies and collected real examples. We divide our ty-
pology into direct imperfections, indirect imperfec-
tions and granularity. The direct ones are those which
can be deduced directly from the given data: uncer-
tainty, typing error, imprecision, missing and useless-
ness. The Indirect imperfections are those that can be
deduced from the direct ones. We distinguish three
types of indirect imperfections: (i) The incoherence
can be generated from the uncertainty and typing er-
ror. (ii) The incompleteness can be generated from
the imprecision and the missing. (iii) The redundancy
can be generated from the uselessness. Granularity is
the general context of the given temporal data which
can determine the type of imperfection.
3.1 Direct Imperfection Types
We distinguish seven direct imperfection types: un-
certainty, typing error, imprecision, missing, circum-
locution and uselessness which will be detailed one
by one and illustrated by examples.
Uncertainty. According to (Smets, 1999), each
statement is whether true or false. However, the
knowledge about the statement, if it is uncertain,
does not allow you to decide either it is true or
false. Uncertainty is partial knowledge of the true
value of the data. It is the lack of information.
In our typology, uncertainty has two categories.
The first category includes uncertain data that re-
spect the rules of common sense. It can be due
to a doubt. As an example, ”I’m not sure if it
was the last summer or the one before when my
aunt came from Paris to spend the holidays with
us”. In this example, the person is doubting about
the given temporal data. However, the latter re-
A Typology of Temporal Data Imperfection
307
Figure 1: Our typology of temporal data imperfection.
spects the rules of common sense. The second
category includes unreliable uncertain data in re-
lation to the general rules of common sense. For
example, ”We swam in the sea during the new
year holiday”. This data does not respect the rules
of common sense since the new year holidays are
in winter and not in summer.
Typing Error. In some cases like using a sys-
tem, the entered data by the user may be subject
to errors. For instance, if we have the informa-
tion ”The municipality employee typed my date
of birth wrongly”, the inserted date of birth is a
typing error imperfection.
Imprecision. Most of the temporal data are im-
precise. Imprecision leads to the ambiguity about
the information. Imprecise temporal data has two
categories. The first one includes the ones that
are translatable to perfect data. For example, ”We
moved to Tunis by 2008”.”by 2008” is a numeric
temporal data that can be translatable to a perfect
interval that has two bounds (2007 .. 2009). An-
other example, if we have the information Dur-
ing the summer vacation, they travelled to Spain
”. ”During the summer vacation” presents a nat-
ural language-based temporal data which can be
translatable to a perfect temporal interval [01/06
.. 31/08] since the bounds are precise. The
second category includes the ones that are non-
translatable to perfect data. Several examples can
be introduced, such as ”I moved to my new job
after my daughter’s birth”; ”After my daughter’s
birth” is imprecise since her daughter’s birth is un-
known. Another example is ”He was sick before
his death”; ”Before his death” is also imprecise
since we do not know how much time before his
death he was sick. Another type of natural lan-
guage based temporal data that is non-translatable
to perfect data is the adverbs of time such as
Nowadays”, ”Currently”, ”Now” and ”later”.
Missing. Temporal data may be subject to a
missing. Missing can be either partial or total. For
example, the following data ”It was in March but
I forget the year”. In this example, the missing
is partial. The person remembers the month how-
ever he forgets the year. Another example, if we
have the information ”I forget when last time I vis-
ited my aunt who lives in Paris”. In this example,
the missing is total. The person forgets totally the
temporal data.
Circumlocution. Temporal data can be the ob-
ject of a circumlocution. For example, ” The first
day of the week, we will have a work meeting”.
The person used ” the first day of the week” state-
ment, however he means ”Monday”. Another ex-
KEOD 2019 - 11th International Conference on Knowledge Engineering and Ontology Development
308
ample, ”The marriage is two days after the week-
end”. The person replaces ”Tuesday” by the state-
ment ”two days after the weekend”.
Uselessness. This imperfection means that the
given information is useless and there is not any
added value to the given information. For ex-
ample, if we have the information ”During the
Christmas in December, people celebrate all over
the world”, it is very enough to say ”During the
Christmas” since it is a general truth that the new
year is obviously in December. Therefore, in this
case, ”in December” presents a useless temporal
information.
3.2 Indirect Imperfection Types
We distinguish three indirect imperfection types: in-
coherence, incompleteness and redundancy. These
imperfections are deduced from the direct imperfec-
tion types.
Incoherence. To define the incoherence, we are
based on on (Gavignet et al., 2016). According
to her, the incoherence refers to ”the existence of
contradictory data on the same object”. Thus, un-
certainty and typing error that can exist in a given
temporal data may lead to the incoherence.
Incompleteness. Missing and imprecise tempo-
ral data may lead to an incompleteness. For in-
stance, if we have the information ”My uncle will
come next weekend”; ”next weekend” is impre-
cise and, so incomplete. It could be ”Saturday” or
”Sunday”.
Redundancy. It can be concluded when use-
lessness interferes in the given temporal data. For
instance, if we have the information ”A long time
ago, my grand-parents dead. It was several years
ago”, in this statement the person indicates two
temporal data, ”A long time ago” and ”several
years ago”, that give the same meanings, which
is useless and redundant.
3.3 Context - Dependent Temporal Data
Granularity presents the scale or level of detail in a
set of data. The context of a given temporal data de-
termines the type of imperfection. For instance, if we
have ”We can meet next weekend”; ”next weekend”
is imprecise. It could be ”Saturday” or ”Sunday” or
both. However, if we have ”We will spend next week-
end in Berlin”, it is clear from the context that “next
weekend” means the whole weekend (i.e., both of Sat-
urday and Sunday) and thus the data is precise. Be-
sides, several factors may interfere in determining the
type of imperfection such as the profile of person and
multiculturalism.
The Profile of the Person. From the person
themselves we can decide the type of imperfec-
tion. For instance, the temporal data given by an
Alzheimer’s patient is probably uncertain. For ex-
ample I am not sure it was in the morning or at
night ”. Another example concerns the children
who frequently get confused about ”yesterday”,
”tomorrow” and ”today”.
Multiculturalism. Multiculturalism aspect re-
flects the cultural differences where ideas are fo-
cused on the beliefs ways of societies. For in-
stance, ”the weekend” in Europe is ”Saturday and
Sunday”. It differs from the one in the Arab World
which is ”Friday and Saturday”.
4 REPRESENTING EXAMPLES
OF IMPRECISE TEMPORAL
DATA IN PERSONLINK
ONTOLOGY
In this section, we represent some examples of im-
precise temporal data in PersonLink
1
ontology based
on our previous work (Ghorbel et al., 2018) in which
we extend the 4D-fluents approach (Welty, 2006) to
represent imprecise time intervals and crisp temporal
interval relations.
Let’s have the following example: ”Peter was
married to Stephanie just after he was graduated with
a PhD and it lasts 15 years. Peter was graduated with
a PhD in 1960”. This example contains a natural
language-based temporal data which is ”just after he
was graduated” . It is an imprecise temporal data. Let
I = [I
, I
+
] be an imprecise time interval representing
the duration of the marriage of Peter and Stephanie.
Assume that I
= {1960...1963} presents the inter-
val of the beginning bound and I
+
= {1975...1978}
the interval of the ending bound. Figure 2 illustrates
a part of PersonLink ontology which represents this
example.
Another example, we consider the following in-
formation: “John was married to B
´
eatrice since about
10 years. John was married to Maria just after he
was graduated with a PhD and it lasts 15 years. John
was graduated with a PhD in 1980”. Let I = [I
, I
+
]
and J = [J
, J
+
] be two imprecise time intervals rep-
resenting, respectively, the duration of the marriage
of John and B
´
eatrice and the one of John and Maria.
1
http://cedric.cnam.fr/ hamdif/ontologies/files/
PersonLink.html
A Typology of Temporal Data Imperfection
309
Figure 2: Representation of the first example of imprecise
temporal data in PersonLink.
Assume that I
= {2007...2009}, I
+
= 2018, J
=
{1980...1983} and J
+
= {1995...1998}. Figure 3 il-
lustrates this example.
Figure 3: Representation of the second example example of
imprecise temporal data in PersonLink.
5 CONCLUSION AND FUTURE
WORK
In this paper, we introduce our typology of tempo-
ral data imperfection. It is classified into direct im-
perfections of both numeric temporal data and natural
language based temporal data, indirect imperfections
that can be deduced from the direct ones and granular-
ity (i.e., context - dependent temporal data) which is
related to several factors such as person’s profile and
multiculturalism.
Direct imperfections consist of uncertainty, typing
error, imprecision, missing, circumlocution and use-
lessness. Indirect imperfections are generated from
the direct ones. Uncertainty and typing error lead to
the Incoherence. Imprecision and missing lead to in-
completeness. Uselessness leads to redundancy.
We finish by representing an example of imprecise
temporal data in PersonLink ontology.
As for continuity of our work, we plan to pursue
on treating the other proposed types of temporal data
imperfections in our typology starting by the uncer-
tainty.
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