D2.2 Quality Frame Report · The ISO 19100-series were prepared by Technical Committee ISO/TC211, Geographic information / Geomatics. For the quality of geographic data are especially

Report on quality frame for information

Project acronym: EDC-11145 EUROROADS/28646 Deliverable: D2.2 Nature: Public Author: Thomas Wiltschko, Thilo Kaufmann Date: 12 October 2004 Version: 1.0 Status: Final

WP2 Date Status Version Page D2.2 Quality frame for information 12.10.04 Final 1.0 2 (37)

Document control: Version Date Editor Comment

0.1 03/09/2004 Thomas Wiltschko, Thilo Kaufmann

draft sent to WP2 for comments


draft sent to PMG for comments and approval


Final sent to PMG

WP2 Date Status Version Page D2.2 Quality frame for information 12.10.04 Final 1.0 3 (37) 1 Introduction.......................................................................................................... 5

1.1 Aims and scope............................................................................................ 5 1.2 Methodology and sequence ......................................................................... 5

2 Investigation of quality concepts for geoinformation............................................ 6

2.1 Standards..................................................................................................... 6 2.1.1 Quality concept of ISO 19100-series..................................................... 6

2.1.2 Quality concept of ENV 12656 .............................................................. 8

2.1.3 Quality concept of FIPS 173.................................................................. 9

2.2 Quality concepts in geoinformation models................................................ 10 2.2.1 Quality concept of GDF....................................................................... 10

2.2.2 Quality concept of ATKIS .................................................................... 12

2.2.3 Quality concepts of geoinformation models in European countries..... 12

2.3 Résumé: Quality concepts in the standards ............................................... 13 3 Questionnaire for evaluation of quality model.................................................... 14

3.1 Introduction to the questionnaire of quality model ...................................... 14 3.2 Material and methods................................................................................. 15 3.3 Analysing and discussion of the results...................................................... 15

4 Quality Model for quality assurance in geoinformation processes..................... 16

4.1 Motivation................................................................................................... 16 4.2 Quality characteristics ................................................................................ 23

4.2.1 Dependability characteristics............................................................... 23

4.2.2 Integrity characteristics ....................................................................... 24

4.2.3 Accuracy characteristics ..................................................................... 26

4.3 Quality parameter....................................................................................... 26 4.3.1 Quality parameter for availability ......................................................... 26

4.3.2 Quality parameter for up-to-dateness.................................................. 27

4.3.3 Quality parameter for completeness ................................................... 27

4.3.4 Quality parameter for consistency....................................................... 27

4.3.5 Quality parameter for correctness ....................................................... 27

4.3.6 Quality parameter for accuracy ........................................................... 28

5 Conclusion and Outlook .................................................................................... 29

Annexes.................................................................................................................... 31

Annexe A: Glossary .............................................................................................. 31 Annexe B: Questionnaire ...................................................................................... 32


Annexe C: Literature ............................................................................................. 36


1 Introduction

1.1 Aims and scope In work package 2.2 of the EU-project EuroRoadS a quality model for quality assurance in geoinformation processes is to be specified. Therefore the existing standards in the field of geoinformation quality as well as quality concepts of EuroRoadS-participants were investigated. Furthermore a questionnaire regarding quality characteristics and parameters for geoinformation was evaluated by EuroRoadS-participants. Based on these investigations a quality model was created. The difference to existing approaches is, that the quality model should be used within geoinformation processes and not only for a geographic dataset.

Quality is defined in ISO 9000 (2000) as „degree to which a set of inherent characteristics fulfils requirements“. Therefore the objective for work package 2.2 is to define a set of inherent quality characteristics, which

• can describe all quality phenomenon non-ambiguously

• can be used within the information chain

• can be transferred from existing quality models

• can be used by all actors (data provider, information provider, content provider, service provider)

Thus the EuroRoadS quality model is developed for quality assurance in geoinformation processes. Based on this quality model in following work package 2.3 a probabilistic model will be developed to evaluate the geoinformation quality within the complete information chain.

1.2 Methodology and sequence The EuroRoadS deliverable D2.2 “Report on quality frame for information” is structured as follows: First existing quality concepts for geoinformation were investigated (Chapter 2). Based on this comparison of existing standards a questionnaire and the results of this evaluation were analysed (Chapter 3). Finally a quality model for quality assurance in geoinformation processes were derivated (Chapter 4). Furthermore the main results are concluded and an outlook is given (Chapter 5).


2 Investigation of quality concepts for geoinformation In the following the basics of quality concepts for geoinformation in standards (ISO 19100-series, FIPS 173, ENV 12656) and selected geoinformation models (GDF, ATKIS, and others) will be explained.

2.1 Standards

2.1.1 Quality concept of ISO 19100-series

2.1.1.1 Basics The ISO 19100-series were prepared by Technical Committee ISO/TC211, Geographic information / Geomatics. For the quality of geographic data are especially the standard „ISO 19113 Quality principles“ and „ISO 19114 Quality evaluation procedures“.

The scope of ISO 19113 is describing the quality of geographic data and specifies components. This standard is applicable to data producers. It can be extended to identify, collect and report the quality information for a geographic dataset, dataset series, subset of a dataset (SIS 2003).

The international standards of ISO can be taken as European resp. national standards. The national standardisation organisation of the participating countries are members of ISO/TC211 (JOOS 2002).

At the same time as ISO/TC 211 also the Open GIS Consortium (OGC) was founded. OGC is a non-profit-orientated society of companies, authorities, organisations and universities. Being based on the same aims and a considerable overlapping of the working fields a cooperation agreement was decided in 1998. Since that time OGC successively has taken over the ISO-standards as abstract specifications and has developed implementation specifications. These are submitted to ISO and can become an international standard by passing a voting process. Thus OGC has not developed own quality standards (JOOS 2002).

2.1.1.2 Description of quality In „ISO 19113 Geographic Information - Quality principles“ five data quality elements are defined: completeness, logical consistency, positional accuracy, temporal accuracy, thematic accuracy. These shall be used to describe how well a dataset meets the criteria set forth in its product specification. For the data quality elements the data quality subelements shall be used to describe aspects of the quantitative quality of a dataset.


Tab. 1: Data quality elements and subelements of ISO 19113 (own arrangement according to SIS 2003)

data quality elements

data quality subelement

description (SIS 2003)

presence and absence of features, their attributes and relationships

commission excess data present in a dataset

completeness

omission data absent from a dataset degree of adherence to logical rules of data structure, attribution

and relationships (data structure can be conceptual, logical or physical)

conceptual consistency

adherence to rules of the conceptual schema

domain consistency adherence of values to the value domains format consistency degree to which data is stored in accordance with the physical

structure of the dataset

Logical consistency

topological consistency

correctness of the explicitly encoded topological characteristics of a dataset

accuracy of position of features absolute or external accuracy

closeness of reported coordinate values to values accepted as or being true

relative or internal accuracy

closeness of the relative positions of features in a dataset to their respective positions accepted as or being true

Positional accuracy

gridded data position accuracy

closeness of gridded data position values to values accepted as or being true

accuracy of the temporal attributes and temporal relationships of features

accuracy of a time measurement

correctness of the temporal references of an item (reporting of error in time measurement)

temporal consistency

correctness of ordered events or sequences, if reported

Temporal accuracy

temporal validity validity of data with respect to time accuracy of quantitative attributes and the correctness of non-

quantitative attributes and of the classifications of features and their relationships

classification correctness

comparison of the classes assigned to features or their attributes to a universe of discourse (e.g. ground truth or reference dataset)

non-quantitative attribute correctness

correctness of non-quantitative attributes

Thematic accuracy

quantitative attribute accuracy

accuracy of quantitative attributes

WP2 Date Status Version Page D2.2 Quality frame for information 12.10.04 Final 1.0 8 (37) Furthermore there are the following data quality overview elements where applicable shall be used to describe the non-quantitative overview element usage:

Tab. 2: Data quality overview elements of ISO 19113 (own arrangement according to SIS 2003)

2.1.2 Quality concept of ENV 12656

2.1.2.1 Basics The European Prestandard ENV 12656 was approved by the European Committee for Standardization (CEN) as a prospective standard for provisional application. This prestandard establishes general principles for describing the quality of geographic information and provides scheme for describing data quality. This includes details of the lineage and usage of particular sets of geographic information and the results of measures of quality either against a pre-established scale or relative to similar information. It is applicable for suppliers as well as for users of dataset (CEN 1998).

The European Prestandard ENV 12656 includes a quality schema. The objective of this quality scheme is to define the relation between specifications and performance of (parts of) geographic datasets by a set of quality elements (CEN 1998).

2.1.2.2 Description of quality In the European Prestandard ENV 12656 the quality is described by quality elements. In this prestandard a quality element is defined as an “item of information describing the quality of a geographic dataset” (CEN 1998). There are four main elements and their definitions according CEN (1998):

• lineage is the description of the history of the geographic dataset in terms of source material, dates, processing applied and responsible organisations.

• usage shall consist of the name of an organisation that has used the geographic dataset; the type of usage by that organisation; any constraints or limitation that were imposed or found during use; the date when the geographic dataset was used.

• homogeneity is a textual and qualitative description of expected or tested uniformity of quality parameters in a geographic dataset.

• quality parameters describe measurable aspects of the performance of a geographic dataset.

With regard to the aim of definition of a set of inherent quality characteristics for EuroRoadS the quality parameters of ENV 12656 are illustrated more detailed:

data quality overview element

description (SIS 2003)

Purpose shall describe the rationale for creating a dataset and contain information about its intended use.

Usage shall describe the application(s) for which a dataset has been used. Usage describes uses of the dataset by the data producer or by other, distinct, data users.

Lineage shall describe the history of a dataset and, in as much as is known, recount life cycle of a dataset from collection and acquisition through compilation and derivation to its current form

WP2 Date Status Version Page D2.2 Quality frame for information 12.10.04 Final 1.0 9 (37) quality parameters possible quality indicators quality measures

horizontal bias and rmse relative horizontal accuracy horizontal threshold vertical bias and rmse relative vertical accuracy vertical threshold

positional accuracy

user defined user defined accuracy of classification percentage correctly classified agreement for an attribute percentage of agreement

semantic accuracy

user defined user defined temporal accuracy user defined (e.g.: last update) (e.g. date of last update)

omission percentage of entities missing commission percentage of entities in excess

completeness

user-defined user defined logical consistency user-defined (e.g.: geometric consistency) (e.g. percentage of non-repeated points in

the same geometric primitive)

Tab. 3: Quality parameter, quality indicators, quality measures in ENV 12656 (own arrangement according to CEN 1998)

2.1.3 Quality concept of FIPS 173

2.1.3.1 Basics The Federal Information Processing Standards (FIPS) are issued by the National Institute of Standards and Technology (NIST) in USA. The FIPS publication 173 from July 1992 is the Spatial Data Transfer Standard (SDTS) (FEGEAS ET AL. 1992). This standard provides specifications for the organization and structure of digital spatial transfer, definition of spatial features and attributes, data transfer encoding, and topological vector profile. The purpose of the standard is to promote and facilitate the transfer of digital spatial data. This standard was initiated by the National Committee for Digital Cartographic Data Standards (NIST 1994).

FIPS 173 consists of three parts: Part 1 is concerned with logical specifications required for spatial data transfer, and itself consists of three major sections: a conceptual model for spatial, components of a data quality report and a detailed logical transfer. Part 2 includes the model for the definition of spatial features (entities), attributes, and attribute values. Part 3 specifies the implementation of the logical specifications in Part 1 of SDTS using a general data-exchange standard (FEGEAS ET AL. 1992 ).

2.1.3.2 Description of quality Five components of quality are specified in FIPS 173: Lineage, positional accuracy, attribute accuracy, logical consistency, completeness. Temporal information is relevant in each part. The SDTS data quality report specifications are flexible and extensible. A data quality report can relate metadata to any level of a transfer: the entire dataset, selected themes or maps, or individual features and spatial objects (FEGEAS ET AL. 1992).

WP2 Date Status Version Page D2.2 Quality frame for information 12.10.04 Final 1.0 10 (37) portions description (MORRISON 1995) lineage the lineage portion of a quality report shall include a description of the source material from

which the data were derived, and the methods of the derivation, including all transformations involved in producing the final digital files

positional accuracy

the quality report portion on positional accuracy shall include the degree of compliance to the spatial registration standard

attribute accuracy

attribute assessment for measures on a continuous scale shall be performed using procedures similar to those used for positional accuracy

logical consistency

shall describe the fidelity of relationships encoded in the data structure of the digital spatial data

completeness the quality report shall include information about about selection criteria, definitions used and other relevant mapping rules (e.g. geometric thresholds such as minimum area or minimum width). The report on completeness shall describe the relationship between the objects represented and the abstract universe of all such objects. In particular it shall describe the exhaustiveness of a set of features.

Tab. 4: Quality components and indicators in FIPS 173 (own arrangement according to MORRISON 1995)

2.2 Quality concepts in geoinformation models

2.2.1 Quality concept of GDF

2.2.1.1 Basics The beginnings of GDF (Geographic Data File) are in the middle of the eighties. GDF is an EU-plan started on the instigation of vehicle and sub-supplier industry, leading later to a standardised CEN-format for traffic geographic data. It was developed to satisfy the needs arising in acquisition, actualisation and applying of referenced and structured traffic net data. At the beginning of the nineties GDF was standardised and today it serves as basis for digital road data in vehicle navigation systems as well as a basis for the development of Intelligent Transport Systems (ITS) (UNIVERSITY ROSTOCK 2004). Leading enterprises for digital road nets (Tele Atlas, NAVTEQ) supply their road data among other things in GDF-format.

GDF specifies a system for the interchange of digital road related geographic information. It takes into account all the requirements of applications in the road transport and traffic telematic field. The standard contains the following detailed specifications:

• A reference model according to which the information covered by the standard shall be defined. The core of the reference model is formed by a data model and a data dictionary in which the individual information components and their interrelations are defined.

• A specification of way of representation of the information components contained

• The specification how to define a meta information. An important aspect is the quality of the information defined according to the standard.

• A specification for an exchange format reflecting the reference model. (CEN TC 278:1995)

WP2 Date Status Version Page D2.2 Quality frame for information 12.10.04 Final 1.0 11 (37) 2.2.1.2 Description of quality In order to describe the quality of a digital map, the content of a dataset must be compared to the real world situation which the digital map represents. Depending on the purpose of the digital map, conformance to reality must be achieved within defined limits. A quality checking process requires the definition of standardized quality measuring methods and the assignment of quality levels to each measurement. The measuring methods enable a reasoned assessment of whether the quality of a digital map is sufficient. The checking process will help the evaluator to decide whether to accept or reject datasets based on the assigned level (CEN TC 278:1995). The following definitions describe which quality aspects are used for the quality measurement methods and checking in GDF: descriptive Terms

sub-itmes description (CEN TC 278:1995)

the smallest unit of measurement which can be described by means of attribute values or coordinate values (e.g. if coordinates are rounded to within 0.5 m the spatial resolution will be 0.5 m). The resolution provides a limit to precision and accuracy. It can be used to qualify attributes and coordinates.

resolution

dataset XY Resolution

planimetric resolution

precision the closeness of measurements of the same phenomenon repeated under essentially the same conditions and using the same technique (calculation as standard deviation of a single observation). Precision is used to qualify a specific digitizing operation or any kind of elementary operation of data capturing.

the deviation from the results of observations, computations, or estimates to true values or the values which are accepted as being true. In a GDF, accuracy is used for the qualification of coordinate values and quantitative attribute values.

dataset XY accuracy

planimetric accuracy

dataset Z accuracy

height accuracy

accuracy

dataset relative accuracy

relative attribute accuracy

whether a real world data item is correctly recorded according to a specified data catalogue.

correctness

dataset correctness

minimum correctness rate in the attribute values derived from the corresponding values

the percentage of data items which are actually in the dataset compared with the items that should be in it.

dataset feature completeness

feature completeness anywhere in the dataset

completeness

dataset attribute completeness

attribute completeness anywhere in the dataset

up-to-dateness (currency)

this is specified by: - the date of survey (not date of publication); - the ageing rate of the elements in that dataset. - the ageing rate of a particular data item is the percentage, that appear disappear, or change in one or more of its relevant characteristics within a given period. The ageing rate has an effect on the Completeness and Correctness. Therefore, Up-to-dateness is measured within Completeness and Correctness.

WP2 Date Status Version Page D2.2 Quality frame for information 12.10.04 Final 1.0 12 (37) descriptive Terms

sub-itmes description (CEN TC 278:1995)

dataset mean survey date

average survey date

dataset maximum age

maximum age of any item in the entire dataset

Tab. 5: Descriptive terms and sub-items for data quality of geographic datasets in GDF (own arrangement according to CEN TC 278:1995)

2.2.2 Quality concept of ATKIS

2.2.2.1 Basics It is the duty of the survey authorities of the German Federal States to deliver geographic data bases to administration, industry and private users. For this purpose data of the topographic survey within the project ATKIS (Àuthoritative Topographic-Cartographic Information System`) are digitally collected, centralized all over Germany, updated and placed at disposal. The aim of ATKIS is a consistent digital topographic data basis for objects, shapes and the relief of the earth surface. ATKIS can dispose of descriptions of the earth surface as digital landscape models (DLM), digital terrain models (DGM), digital topographic maps (DTK) and digital orthophotos (DOP).

2.2.2.2 Description of quality The common data model AFIS-ALKIS-ATKIS provides collecting and updating of quality data on the basis of ISO-standards “ISO 19113 Geographic Information – Quality Principles” and “ISO 19114 Geographic Information – Quality Evaluation Procedures”. They are differentiated according to non-quantifiable overview information and quantifiable information (ADV 2004 ).

purpose usage

non-quantifiable overview information

history completeness logical consistency geometric accuracy semantic accuracy

quantifiable information

temporal accuracy

Tab. 6: Quality information in ATKIS (own arrangement according to ADV 2004)

2.2.3 Quality concepts of geoinformation models in European countries

2.2.3.1 Institut Géographique National (IGN), France In the IGNF road database „GEOROUTE“ are used five quality parameters like in ISO 19100-series: geometric accuracy, data currency, completeness, semantic accuracy and logical consistency.

data quality elements comments (IGNF) geometric accuracy root mean square of errors in XY data currency update


data quality elements comments (IGNF) completeness omission rate (deficit)

commission rate (excess) semantic accuracy misclassification rate for different attributes logical consistency

Tab. 7: Quality concept of IGNF (own arrangement according to IGNF 2004)

2.2.3.2 National Land Survey of Sweden (Lantmäteriet), Sweden In the quality concept of Lantmäteriet, National Land Survey of Sweden, the following data quality elements are used:

data quality elements comments (Lantmäteriet 2004) completeness logical consistency positional accuracy in plane and height thematic accuracy clustering attributes into types currency periodical and continuous updating

Tab. 8: Quality concept of Lantmäteriet (own arrangement according to Lantmäteriet 2004)

2.3 Résumé: Quality concepts in the standards The comparison between quality elements, components, parameters, aspects and information (further on only the comprehensive term “quality elements” is used for better legibility) in Tab. 9 shows how different geographic data quality is documented in the individual standards and geoinformation models. Even the terms of the various parts of quality description show differences.

quality concept of notation ISO 19113 quality elements, quality sub-elements ENV 12656 quality elements, quality parameters, quality indicators, quality

measures FIPS 173 components GDF descriptive terms, sub-items ATKIS information

Tab. 9: Different terms in quality documentation for standards

The systematic of quality documentation is different in all standards, therefore not all parts could be classified in the same way. Otherwise some certain similarities can be recognized in design and use of quality elements resp. quality components. As seen above the quality elements` completeness and accuracy can be found in all investigated standards and geoinformation models. In addition to logical consistency the important quality elements` completeness and accuracy are included in ISO 19113. Also the quality elements of ATKIS, FIPS 173 and DIN V ENV 12656 are comparable to ISO 19113. The quality concept of GDF includes some more quality elements like correctness and up-to-dateness.

In general 2 types of quality elements can be differentiated:


• elements of which a direct quality statement can be made (e.g. completeness)

• elements of which only conclusion to quality can be drawn, but no direct statement can be made (e.g. lineage).

quality elements, of which direct

statement can be made: ISO 19113 DIN V ENV

12656 FIPS 173 GDF ATKIS

completeness X X X X X logical consistency X X X X positional accuracy X X X X X temporal accuracy X X X

thematic / semantic / attribute accuracy

X X X X X

resolution X precision X

correctness X up-to-dateness X

quality elements, of which no direct statement can be made:

ISO 19113 DIN V ENV 12656

FIPS 173 GDF ATKIS

lineage X X X homogeneity X

quality documentation X purpose X X usage X X

history X

Tab.10: Overview on quality elements in investigated quality concepts, where (no) direct quality statement can be made

For specification of the quality model of EuroRoadS quality elements of which a direct quality statement can be made shall be used, as only this can give a clear statement concerning quality of a geographic dataset. Elements of second kind (see Tab.10), as for example “lineage” or “purpose” can not be included directly into the quality model of EuroRoadS, as, for example by data origin, no explicit quality statement can be made. Those statements as, for example of the lineage, could possibly serve besides quality information as a further kind of metadata.

3 Questionnaire for evaluation of quality model

3.1 Introduction to the questionnaire of quality model The Institute for Applications of Geodesy to Engineering (IAGB), University of Stuttgart, designed – based on the investigations of the existing standards in the field of geoinformation quality – a questionnaire for evaluation of quality framework. This draft questionnaire was presented at EuroRoadS-meetings by IAGB. Based on the comments and feedbacks from participants of EuroRoadS the questionnaire was revised by IAGB. Then the questionnaire was send by email to the participants of EuroRoadS and participants of the "Expert Group on

WP2 Date Status Version Page D2.2 Quality frame for information 12.10.04 Final 1.0 15 (37) Quality" of EuroGeographics in June 2004 and answers were requested in July 2004. The results were presented at EuroRoadS-meeting in Brussels in September 2004.

The objective of the questionnaire was to find out which quality characteristics and parameters of geoinformation are important from the point of the different participants. Therefore quality characteristics and parameters were valuated, chosen and completed by the different participants.

3.2 Material and methods The questionnaire was send to the participants of the EU-project EuroRoadS as well as the members of the "Expert Group on Quality" of EuroGeographics; there were 6 answers received from 5 countries. Of the answers 4 were from National Mapping Agencies, 1 from a Road Administration and 1 from a private enterprise.

The National Mapping Agencies were:

• Federal Office of Metrology and Surveying (BEV), Austria

• Institut Géographique National (IGN), France

• National Land Survey of Sweden (Lantmäteriet), Sweden

• Ordnance Survey (OS), Great Britain

The Road Administration was:

• Vägverket (VV), Sweden

The private enterprise working with road data and services concerning traffic management and related areas was:

• Planung Transport Verkehr AG (PTV),Germany

3.3 Analysing and discussion of the results The following results are based on a quantitative analysis (the filled in questionnaires from 6 institutions) and a qualitative analyse (the comments and descriptions from 3 institutions):

• the quality model should be based on the ISO terminology

• the asked providers used less quality elements than postulated in ISO 19113 (àctual state`). But on the other hand in the questionnaire the asked providers evaluated, that more quality elements are useful than postulated in ISO 19113 (`should-be state`).

• The quality characteristics and parameters, not contained in ISO 19113, but suggested for the EuroRoadS quality model, were confirmed by the evaluation results of the questionnaire (e.g. availability).

In Tab. 11 the results of the actual investigation (2004) and the investigation of Jakobsson & Vauglin (2001) are compared. In the investigation of Jakobsson & Vauglin (2001) 21 National Mapping Agencies were queried among others, which quantitative quality elements and parameters (according to CEN/TC 287 and ISO TC 211 definitions) they use. As result it is to point out, that the study of Jakobsson & Vauglin (2001) shows that the asked national mapping agencies use less quality elements than in ISO 19113 postulated (àctual state`). On

WP2 Date Status Version Page D2.2 Quality frame for information 12.10.04 Final 1.0 16 (37) the other hand in the actual investigation the asked providers evaluated, that more quality elements are useful than postulated in ISO 19113 (`should-be state`). In particular it is interesting, that the new quality characteristics, proposed in the actual questionnaire – i.e. availability, up-to-dateness and correctness – are assessed as very important.

quality elements of

Jakobsson & Vauglin (2001)

% of NMAs using

quality characteristics of actual questionnaire (2004)

degree of importance (0% = less important 100% = very important)

purpose

57% -- --

usage

48% -- --

lineage

71% lineage 65%

non-quantitative quality elements

user-defined

5% -- --

-- -- availability

88%

-- -- up-to-dateness 83%

completeness

52% completeness 92%

logical consistency 62% logical consistency 88%

--

-- correctness 83%

positional accuracy 62% positional accuracy 83%

thematic accuracy 38% thematic accuracy 75%

quantitative quality elements

temporal accuracy 38% temporal accuracy 63%

Tab. 11: Use of quality elements (àctual state`) vs. degree of importance (`should-be state`).

4 Quality Model for quality assurance in geoinformation processes

4.1 Motivation As shown in chapter 2 the existing quality concepts as ATKIS, FIPS 173, DIN ENV 12656 are close to the quality model of ISO 19113. This concept is unfortunately not exactly usable for EuroRoadS, because the scope of EuroRoadS is to use a quality model within the whole information chain and not only for a dataset from data producers. The scope of the quality

WP2 Date Status Version Page D2.2 Quality frame for information 12.10.04 Final 1.0 17 (37) concept in EuroRoadS is different to the quality concept of ISO 19113. The main differences are shown in Tab. 12:

Quality model of ISO 19113 Quality model of EuroRoadS − Applicable for data producers: describe and

assess how well a dataset meets the product specification

− Applicable for data user: determine whether or

not specific geographic data as of sufficient quality for their application

− Can be extended to identify, collect and report

the quality information for a geographic dataset, dataset series, subset of a dataset

− Some quality characteristics can be used only for

special data types (geometric, thematic, temporal)

− Applicable for data provider, content provider, information provider and service provider within the whole information chain

− Applicable to describe quality within

geoinformation processing − Can be used for geographic datasets, dataset

series, subset of a dataset as well as features and attributes.

− The set of inherent quality characteristics can be

used for all data types (geometric, thematic, temporal). The differentiation regarding data types happens at the level of the quality parameter

Tab. 12: Scope of quality model of ISO 19113 and of EuroRoadS

To fulfil the scope of EuroRoadS it is necessary to have a set of inherent quality characteristics. Quality is defined in ISO 9000 (2000) as „degree to which a set of inherent characteristics fulfils requirements“. Based on this definition the main objective of this work package is that the quality of geographic data is described non-ambiguously by a set of inherent quality characteristics. But only by a uniform and objective quality description the quality model can be transferred within a geoinformation chain.

Therefore the following requirements for the quality model of EuroRoadS are to postulate:

• one quality phenomenon (e.g. how actual are the data ?) should be described non-ambiguously by one quality characteristic (e.g. up-to-dateness)

• must be applicable within the whole information chain. Therefore an objective description of all included data by a fixed set of quality characteristics is necessary. In particular geometric, thematic, and temporal data have to be described by the identical set of quality characteristics

• should be transferred from existing quality modelsmust be applicable by all actors within the information chain of geographic data (data provider, content provider, information provider and service provider)

WP2 Date Status Version Page D2.2 Quality frame for information 12.10.04 Final 1.0 18 (37) Thus the EuroRoadS quality model is developed for quality assurance in geoinformation processes. The quality assurance can be carried out in the entire of the geoinformation chain as well as in parts of them like the geoinformation process of a data provider supplying a digital road map (c.f. Fig. 1).

quality assurance

quality assurance

quality assurance

quality assurance

quality assurance

= a fixed set of inherentquality characteristics

processing

DB1

DB2

DBn

Euro

Roa

dS -

Inte

rfac

e

application 1

application n

dataprovider

contentprovider

informationprovider

serviceprovider

quality assurance

quality assurance

quality assurance

quality assurance

quality assurance



processing

DB1

DB2

DBn

Euro

Roa

dS -

Inte

rfac

e

application 1

application n

dataprovider

contentprovider

informationprovider

serviceprovider

Fig. 1: Using of a set of inherent quality characteristics in the geoinformation chain

Based on the requirement that the quality model should be valid within the whole information chain it can be derived that the quality model should not only be usable for a geographic dataset, dataset series and subset of dataset, but it should also be usable for describing quality of feature classes, features and attributes (Fig. 2 ).

set of inherent quality characteristics

qualitycharacteristic1






dataset

feature

attribute

set of inherent quality characteristics







dataset

feature

attribute

Fig. 2: Dependencies between dataset, features, attributes and set of inherent quality characteristics

WP2 Date Status Version Page D2.2 Quality frame for information 12.10.04 Final 1.0 19 (37) It is postulated that it should be a fixed set of inherent quality characteristics. I.e. that one quality phenomenon (e.g. how actual are the data ?) is described by one quality characteristic (e.g. up-to-dateness). Thus a fixed set of inherent quality characteristics is defined. This set will be used for the qualitative description of the quality of geographic data.

Concretion of quality characteristics is effected by the quality parameters (e.g. last update). In opposite to the characteristics a fixed set of quality parameters is not defined, because variable quality parameters depending of different data types are necessary. This means:

• Several quality parameters can be used for one quality characteristic.

• Adequate quality parameter(s) can be used for corresponding data types (e.g. absolute position accuracy for road geometry, attribute accuracy for quantitative attributes and accuracy of time measurements for temporal data)

The quantification of data quality will be carried out by quality parameters. Therefore quality parameter values will be used. E.g. the completeness of a data set will be described qualitatively by quality characteristic completeness. To make the quality characteristic concrete the quality parameter omission rate can be used. The effective omission rate will be formulated by the quality parameter value (e.g. 98 %).

The quality requirements must be formed by quality parameters. The measurement of quality by the quality parameters is dependent on applications and will be determined in the following work package of the EU-project EuroRoadS.

qualityphenomenon1


qualityparameter11

qualityparameter12

qualityphenomenon2


qualityphenomenonn

qualitycharacteristicn

to describe to describe to describe

make concret

qualityparameter21

make concret

qualityparametern1

qualityparametern2

make concret

qualityphenomena

fixed set of inherent quality characteristics

variable quality parameters

qualitymeasure11

qualitymeasure12

qualitymeasure21

qualitymeasuren1

qualitymeasuren2

quality measuresto quality parameters

information quality evaluation procedure

...

...

...

...qualityphenomenon1


qualityparameter11

qualityparameter12

qualityphenomenon2


qualityphenomenonn

qualitycharacteristicn

to describe to describe to describe

make concret

qualityparameter21

make concret

qualityparametern1

qualityparametern2

make concret

qualityphenomena

fixed set of inherent quality characteristics

variable quality parameters

qualitymeasure11

qualitymeasure12

qualitymeasure21

qualitymeasuren1

qualitymeasuren2

quality measuresto quality parameters

information quality evaluation procedure

...

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Fig. 3: Structure of EuroRoadS quality model

The existing quality standard ISO 19113 does not fulfil the postulated requirements, e.g.:

• For example a street segment is digitized wrongly. This phenomenon of a gross error is described in ISO 19113 by the quality element “positional accuracy”. The phenomenon of a random error (e.g. accuracy of digitising tablet) is also described by positional accuracy. Thus two different phenomena are described by one quality element. For a


non-ambiguous quality description by quality characteristics the quality characteristic “correctness” is necessary. The reason of non-correctness is the phenomenon of wrong data acquisition.

• For example, if, in case of a WebGIS-application, the geoinformation is available in the intranet, but, due to a communication error, cannot be transferred into the internet to an external user, availability is not given. Therefore a quality description for availability should be added.

• For example the accuracy for different data types is described in ISO 19113 by different elements (temporal accuracy, thematic accuracy and geometric accuracy). To fulfil the requirement the phenomenon of limited accuracy of data acquisition and storage should be described by only one quality characteristic. The concretion of quality characteristic “accuracy” is effected by variable quality parameters.

Thus the elements of the ISO 19113 should be regrouped and new elements should be added (cf. Fig. 4) to fulfil the postulated requirement.

thematic accuracy

temporal accuracy

positional accuracy

completeness

logical consistency

ISO 19113 geographic informations quality principles

omission comission

conceptual c.domain c. format c.

topological c.

absolute a.relative a.

grid a.

accuracy of time measurementtemporal consistency

temporal validity

classification correctnessNon-quantitative attribute correctness


EuroRoadS - quality model for quality assurance

in geoinformation processes

correctness

consistency

completeness

accuracy

up-to-dateness

omission …

geometric c.…

topological c.

geometric c.thematic c.

topological c.

absolute position a.relative position a.

thematic c.

last updaterate of change

temporal lapse

quality overview elementspurpose

usageLineage (history, …)

availabilityfailure rate …

…

…

… quant. attribute a.

temporal a. of time measurement

thematic accuracy

temporal accuracy

positional accuracy

completeness

logical consistency

ISO 19113 geographic informations quality principles

omission comission

conceptual c.domain c. format c.

topological c.

absolute a.relative a.

grid a.

accuracy of time measurementtemporal consistency

temporal validity

classification correctnessNon-quantitative attribute correctness


EuroRoadS - quality model for quality assurance

in geoinformation processes

correctness

consistency

completeness

accuracy

up-to-dateness

omission …

geometric c.…

topological c.

geometric c.thematic c.

topological c.

absolute position a.relative position a.

thematic c.

last updaterate of change

temporal lapse

quality overview elementspurpose

usageLineage (history, …)

availabilityfailure rate …

…

…

… quant. attribute a.

temporal a. of time measurement

Fig. 4: Connection of “EuroRoadS - quality model for assurance in geoinformation processes” and the “ISO 19113 - quality model for geographic information - quality principles”

With the defined quality model for EuroRoadS a quality frame for geographic data is given that allows a non-ambiguous and objective description of quality of all types and kinds of data within geoinformation processes. In opposite to ISO 19113, where we have gaps at some phenomena, the EuroRoadS quality model has exact one quality characteristic to each quality phenomenon. The ISO 19113 uses different quality elements for different data types in particular for accuracy (cf. Fig. 5). With EuroRoadS quality model each data type will be described by the same six quality characteristics.

WP2 Date Status Version Page D2.2 Quality frame for information 12.10.04 Final 1.0 21 (37) The EuroRoadS quality model contains all quality sub-elements of ISO 19113 by the quality parameter. Thus a data provider can transfer easily his present quality description according to ISO 19113 to EuroRoadS.

availability up-to-dateness

complete-ness consistency correctness accuracy

quality phenomena

geometric

thematic

temporaldata

type

EuroRoadS

complete-ness accuracyavailability up-to-

dateness consistency correctness

positional accuracy



quality phenomena

geometric

thematic

temporal

data

type

ISO 19113

complete-nesslineage thematic accuracy

temporal accuracy

consistency



quality phenomena

geometric

thematic

temporaldata

type

EuroRoadS

complete-ness accuracyavailability up-to-

dateness consistency correctness

positional accuracy



quality phenomena

geometric

thematic

temporal

data

type

ISO 19113

complete-nesslineage thematic accuracy

temporal accuracy

consistency

Fig. 5: Comparison of quality element in ISO 19113 and quality characteristics in EuroRoadS quality model

The fixed set of quality characteristics and the variable quality parameters of the EuroRoadS quality model are shown in Tab. 13. For a better understanding of the quality characteristics’ definition an introduction in the modelling of geoinformation is given.

The geoinformation modelling is, according to SIS (2002), KRESSE & FADAIE (2004), described in steps from reality to data model:

• Each consideration on modelling starts with the real world. The selected piece of the real world that a human being wishes to describe in a model is known as a universe of discourse. This is the view of the real or hypothetical world that includes everything of interest.

• The abstract description of these real-world features is called conceptual model. I.e. the conceptual model defines concepts of a universe of discourse. Conceptual models may be written down and stored for wider dissemination.

• The conceptual scheme is a rigorous formal description of a conceptual model for some universe of discourse. Therefore a conceptual schema language (e.g. UML) is used. This conceptual scheme for data required by one or more applications is the application schema.

• The data model (physical model) describes the exact files or database tables. It includes all data structures and algorithms.

WP2 Date Status Version Page D2.2 Quality frame for information 12.10.04 Final 1.0 22 (37) The use of geographic data is carried out by an application, which has impact to the real world.

availability

application

correctness

up-to-dateness

consistency

completeness geographic data

conceptual modelconceptual schemaapplication schema

data model

real world

universe of discourse

accuracy availabilityavailability

application

correctnesscorrectness

up-to-dateness

up-to-dateness

consistencyconsistency

completenesscompleteness geographic data

conceptual modelconceptual schemaapplication schema

data model

real world

universe of discourse

accuracy

Fig. 6: Dependencies between quality characteristics and geoinformation modelling and processing steps

Based on these different steps the connections of the quality characteristics are shown in Fig. 6. The quality characteristics up-to-dateness, completeness and correctness define the connection between the geographic data and the universe of discourse. A connection to real world would not be meaningful, because only elements which are component of the universe of discourse can be missed or incorrect. The accuracy states also the connection between universe of discourse and geographic data and describes the limitation of measurement and interpretation. The consistency is necessary for the connection between geographic data and models and schemas. The availability describes quality aspects by using the geographic data in an application.

The quality model as well as the definition of the quality characteristics and parameters emanate from a well defined modelling of the universe of discourse. In other words no modelling errors etc. exist, which affect the data quality (e.g. forgotten modelling of turns relationships).


groups of quality

characteristics

quality characteristics Definition possible quality

parameter

failure rate availability degree to which geographic data are available at a certain place and at a defined time

…

last update rate of change temporal lapse

dependability

up-to-dateness degree of adherence of geographic data to the time changing universe of discourse

… omission

commission

completeness degree of adherence of the entirety of geographic data (features, their attributes and relationships) to the entirety of the universe of discourse …

geometric correctness topological correctness thematic correctness

correctness degree of adherence of existence of geographic data (feature(s), attributes, functions, relationships) to corresponding elements of the universe of discourse, up-to-dateness being presumed

…

geometric consistency topological consistency thematic consistency

integrity

consistency degree of adherence of geographic data (data structure, their features, attributes and relationships) to the models and schemas (conceptual model, conceptual schema, application schema and data model)

…

absolute position accuracy relative position accuracy quantitative attribute accuracy temporal accuracy of time measurement

accuracy accuracy degree of adherence of geographic data to the most plausible resp. true value.

…

Tab. 13: Definition of quality characteristics and quality parameters for EuroRoadS quality model for assurance in geoinformation processes

4.2 Quality characteristics

4.2.1 Dependability characteristics The time-dependence of information is represented by the characteristics of dependability. There are the dependability characteristics availability and up-to-dateness.

4.2.1.1 Availability The availability is only fulfilled if the geographic data are available at a required place in time. In addition to the time factor, the place is also a fundamental importance. It is not sufficient that geographic data exist, the geographic data must also be available at the required place and time. Therefore the availability can be defined as “degree to which geographic data are available at a certain place and at a defined time”. For example, if in case of a WebGIS-application the geographic data is available in the intranet, but due to a communication error

WP2 Date Status Version Page D2.2 Quality frame for information 12.10.04 Final 1.0 24 (37) cannot be transferred to the internet to external user, availability is not given. I.e. if the system or a part of it has a failure, availability is not given.

server

application

communication

failure

server

application

communication

failure Fig. 7: Example for availability

4.2.1.2 Up-to-dateness The up-to-dateness describes the degree of adherence of geographic data to the time changing universe of discourse. This is depending on the dynamic of reality and the rate of update. For example, flow regulation at a junction was changed at 12th August 2001 from traffic sign to traffic light. But the regulation of the junction was not changed in the geographic dataset till now. As a result of changes in the course of time the information does not reproduce the reality correctly. The connection between up-to-dateness, correctness and completeness will be considered in the context of the probabilistic model (Deliverable D2.3).

junctionJung_ ID: 123456Y: 3530 994.862X: 5361 004.454regulation: traffic sign

data record out-of- date

universeof discourse

junctionJunc_ID: 123456Y: 3530 994.862X: 5361 004.454regulation : traffic sign

geographic data

18thAugust

200012th

May

2001




data record out-of- date

universeof discourse




geographic data

18thAugust

200012th

May

2001

Fig. 8: Example for up-to-dateness

4.2.2 Integrity characteristics The applicability of geographic data is described by the integrity characteristics completeness, consistency and correctness.

4.2.2.1 Completeness The completeness is only fulfilled if all required features, attributes and relationships of the universe of discourse are in the geographic dataset. For example if the feature “Point of

WP2 Date Status Version Page D2.2 Quality frame for information 12.10.04 Final 1.0 25 (37) Interest” has an Y-value but no X-value the dataset is incomplete, i.e. data absent from a dataset (òmission`). On the other hand an excess data can be present in a dataset (`commission`).

POIY: 3530 994.862X: <no X-value>StrName: SchillerstraßeHousNo: 9

data record incomplete



data record incomplete

Fig. 9: Example for completeness

4.2.2.2 Consistency Consistency is necessary for the connection between geographic data and schemas, which are the basis for the information storage. It is the precondition for a contraction-free data base. Consistency can only be described by boolean values, i.e. a feature, attribute or rule are consistent or not. The consequence of consistency errors are incorrectness and missing availability. In practise consistency has to be checked for a rule, a feature or an attribute.

4.2.2.3 Correctness The correctness means the extent of conformity of geographic data in relation to the universe of discourse. The gross and systematic errors will be considered. These errors are depending on the required accuracy. Possibilities are pictured in Fig. 10: Example (I) shows a incompleteness. Example (II) is incorrect as result of inaccurate digitising, i.e. the digitized street is outside the given accuracy. Example (III) is correct, because the digitized street is inside the given accuracy. The given accuracy of digitising using a digitising table depends on the accuracy of the original manuscript, pointing, and the device. I.e. the cause of non-correctness is digitalisation outside the buffer given by accuracy for the geometry of the road.

10 m10 m10 m10 m

(I) incomplet (II) incorrect (III) correct

streets in conceptual model digitized street

given accuracy

Fig. 10: Example for correctness

WP2 Date Status Version Page D2.2 Quality frame for information 12.10.04 Final 1.0 26 (37) 4.2.3 Accuracy characteristics The aim of the EuroRoadS quality concept is, that one quality phenomenon is described by one quality characteristic. Therefore the phenomenon “how accurate are the data” is described by the one quality characteristic “accuracy”. I.e. that the same quality characteristics should be used for all data types (temporal, thematic, geometric). For example there is a street segment A (including geometry, street classification and temporal constraints) and another street segment B (including only geometry and street classification). For the quality model in the geographic data processes only one quality characteristic should describe the accuracy. This is necessary as ISO 9000 postulated that one quality phenomenon (e.g. how accurate are the data ?) should be described non-ambiguously by one quality characteristics (e.g. accuracy) (cf. Fig. 11). Consequently the concretisation of the general quality characteristic “accuracy” happens at the level of the quality parameter. This possible quality parameter for accuracy will be explained in Chapter 4.3.6 more detailed.

ISO 19113 Geographic information - quality principles

EuroRoadS quality model for quality assurance in geoinformation processes

accuracy phenomenon described by quality characteristics:

absolute positional accuracy

thematic classification accuracy

accuracy of time measurement

accuracy

temporal X X

thematic X X

data

type

geometric X X

Fig. 11: Description of the accuracy of different data types in ISO 19113 and EuroRoadS quality model

4.3 Quality parameter The quality phenomena are described by a fixed set of inherent quality characteristics. Concretion of quality characteristics is effected by quality parameters, which are variable. The exact measurement of quality by functions of quality parameters will be described in further deliverables of work package 2 of the EU-Project EuroRoadS. In the following some possible quality parameters will be explained.

4.3.1 Quality parameter for availability The concretion of “availability” can be effected by failure rate in the physical support. It indicates the degree of probability of a failure of a dataset within an assumed period and can be measured by the function

( ) ( )N

tntR ZV=

whereby the quotient is the number nZV of missing entities at time t and number N of entities in system.

WP2 Date Status Version Page D2.2 Quality frame for information 12.10.04 Final 1.0 27 (37) Quality parameters like “right of use” or “right of change” indicate legal aspects of availability. Technical aspects of availability could be described by “capability or processing” or by “possibilities of access”. All these quality parameters are advanced information, but are not measurable. Therefore they could possibly serve, besides quality information, as a further kind of metadata.

4.3.2 Quality parameter for up-to-dateness Concretion of the up-to-dateness can be effected by comparison between rate of update and rate of change: comparison of how the dataset is changing and how the content in accordance with the universe of discourse is changing. This quality parameter can describe whether the geoinformation is actually valid or not.

4.3.3 Quality parameter for completeness The omission can be measured by the rate of omission

NnCM IC−=1

whereby N is the number of entities in the model of reality and nIC the number of missing entities in the database. The same formula can be used for the commission whereby nIC is the number of excess entities in the database.

4.3.4 Quality parameter for consistency

Concretion of the consistency can be effected by • geometric consistency: percentage of adherence to geometric specification.

• topological consistency: percentage of adherence to the explicitly encoded topological characteristics of a dataset.

• thematic consistency: percentage of adherence to semantic specification.

The consistency can be measured by the function

NnCM IC−=1

whereby nIC is the number of objects, which do not fulfil the consistency requirements (JOOS 2000). In practise most of consistency rules should be automatically checked during production by checking tools. For some of the most important rules a 100% rate is required.

4.3.5 Quality parameter for correctness

Concretion of the correctness can be effected by • geometric correctness: e.g. the geometry is incorrect as result of inaccurate digitising,

i.e. the digitized street is outside the given accuracy (cf. 4.2.2.3).

• topological correctness: e.g. the topology is incorrect as result of wrong relationships, i.e. turn offs in street networks are incorrect, so that the routing results of the networks are wrong.


• thematic correctness: e.g. the thematic is incorrect as result of wrong attribute classification, i.e. an attribute was assigned to a wrong attribute class.

The correctness can be measured by the function

NnCM IC−=1

whereby nIC is the number of incorrect entities and N is the number of entities in the database (JOOS 2000).

4.3.6 Quality parameter for accuracy The concretisation of the quality characteristic “accuracy” can be effected by different quality parameters. It is distinguished between quality parameters for geometric, temporal and thematic data. Therefore the distinction of accuracy happens at the level of the quality parameter.

Accuracy means the relationship between the measured value of the geoinformation and the real value. The accuracy of temporal, thematic and geometric data can be included. The accuracy depends on the required value. A random error will be considered. In case of a gross or a systematic error, it is incorrect (cf. chapter 4.2.2.3). But in practise it is not always possible to know whether an error is systematic or random. Examples for accuracy are:

• temporal: absolute accuracy of temporal values, time measurement, temporal validity

• thematic: absolute accuracy of quantitative attributes (e.g. road width)

• geometric: positional accuracy

absolute accuracy of geometry: closeness of reported coordinate values to values accepted as or being true (e.g. the allowable accuracy for digitisation of streets is 10m)

relative accuracy of geometry: closeness of the relative positions of features in a dataset to their respective positions accepted as or being true

streets in conceptual modeldigitized street

10 m10 m

given accuracy

streets in conceptual modeldigitized street

10 m10 m

given accuracy

Fig. 12: Example for accuracy of continuous data

It is to annotate that relative accuracy is more difficult to manipulate than absolute accuracy.

Accuracy can be measured by standard deviation or variance. For the geometric accuracy of continuous data different quality measures like confidence ellipse are derivable (GLEMSER 2000).


5 Conclusion and Outlook The aim of work package 2.2 of EuroRoadS was to specify a quality model for quality assurance in geoinformation processes. In this connection requirements for the EuroRoadS quality model were postulated:

• One phenomenon must be described non-ambiguously by one quality characteristic.

• Also the quality is to be described objectively within the entire information chain by a fixed set of quality characteristics for different data types (geometric, thematic, temporal).

• It should also be usable for a geographic dataset, dataset series, subset feature, feature classes and attributes.

• Usable by all actors.

As shown these postulated requirements could not be fulfilled completely by existing standards. Therefore a extended quality model was developed, which considers the existing standards. A direct connection to ISO 19113 is given. For the EuroRoadS quality model a fixed set of inherent quality characteristics for an objective and uniform description of quality of geographic data within an information chain was developed (cf. Fig. 13). As shown for each of these quality characteristics a variable number of quality parameters is possible. The quality parameters have a direct connection to the subelements of ISO 19113. A complete list of quality parameters will be defined in the following work package 2.3 for analysing procedures. The detailed modelling of the quality characteristics and parameters will be done with UML in the work package 6.8 metadata catalogue.

integrity characteristics:describe applicability ofinformation

dependability characteristics:describe time related aspect ofinformation quality

accuracy characteristic:describe limitation of accuracyand resolution of measurementand interpretation

fixed

set

of i

nher

ent

qual

ity c

hara

cter

istic

s

correctness

consistency

completeness

accuracy

availability

up-to-dateness

integrity characteristics:describe applicability ofinformation

dependability characteristics:describe time related aspect ofinformation quality

accuracy characteristic:describe limitation of accuracyand resolution of measurementand interpretation

fixed

set

of i

nher

ent

qual

ity c

hara

cter

istic

s

correctness

consistency

completeness

correctness

consistency

completeness

accuracy

availability

up-to-dateness

availability

up-to-dateness

Fig. 13: Fixed set of inherent quality characteristics for EuroRoadS quality model

The quality in ISO 19100 with the elements, sub-elements, and definitions is developed for the scope of datasets, dataset series, and subsets. For EuroRoadS there is an extended application spectrum. Therefore a description for the quality assurance in geoinformation processes is necessary. The necessary extension of ISO 19113 can not be effected completely according to the rules for creating a extension, which are described in ISO 19115. The

WP2 Date Status Version Page D2.2 Quality frame for information 12.10.04 Final 1.0 30 (37) preconditions for an extension will be referred to as far as possible. The extension with the elements availability, up-to-dateness and correctness is conform to the rules for creating a extension. For developing the quality model more stringent, the subelements are to redeploy in dependance to the phenomena. Due to redeployment and extended application spectrum new definitions arise. To avoid misunderstandings the elements are described as characteristics and the subelements are described as parameters within the extended and adapted quality model. The structure, that a element is concreted by a subelement, is kept. Also all subelements are contained in the model extended.

The EuroRoadS quality concept consists of the quality model, which is described in the existing deliverable D2.2, and an analysing procedure, which will be described in the following deliverable D2.3. The probabilistic model will be based on the reliability analysis of mechanical engineering. It will consist of a graphic part for imaging the information flow and a computing part for evaluating the information flow chart. The described quality characteristics and parameters will be the basis for the following probabilistic model. Thus the EuroRoadS quality model is the basis for following quality evaluation procedures to provide quality measures.


Annexes

Annexe A: Glossary Term Definition accuracy Degree of adherence of geographic data to the most plausible resp. true value. accuracy of continuous data

relationship between the measured value of the geoinformation and the real value

availability degree to which geographic data are available at a certain place and at a defined time

commission an excess data presented in a dataset completeness degree of adherence of the entirety of geographic data (features, their attributes and

relationships) to the entirety of the universe of discourse consistency degree of adherence of geographic data (data structure, their features, attributes and

relationships) to the models and schemas (conceptual model, conceptual schema, application schema and data model)

correctness degree of adherence of existence of geographic data (feature(s), attributes, functions, relationships) to corresponding elements of the universe of discourse, up-to-dateness being presumed

failure rate degree of probability of a failure of a dataset within an assumed period integrity the applicability of geoinformation are described by the integrity characteristics omission data absent from a dataset up-to-dateness degree of adherence of geographic data to the time changing universe of discourse. quality degree to which a set of inherent characteristics fulfils requirements quality phenomenon one quality phenomenon is described by one quality phenomenon quality characteristic concretion of quality phenomenon is effected by quality parameter, which are

variable quality parameter several quality parameter can be used for one quality characteristic


Annexe B: Questionnaire 0.1 Date of questioning: ………….......................................

0.2 name of company or authority:

name of contact person:

address:

phone:

email:

…………………….........................

…………………….........................

………………….........................…

……………….......................……..

…………………….........................

0.3 type of provider in the information chain of geographic data:

data provider content provider information provider service provider

0.4 geographic data-based application: ………………………………………

is very important

is less important

1 2 3 4 5

Dependability (the time-dependence of information is represented in the norms by the characteristics of dependability)

1 availability (the extent of existing information at a defined moment and a certain place)

1.1 rights of use (indicate, who has the right to use the dataset)

1.2 possibilities of access (indicate, whether and how to access dataset physically)

1.3 capability of processing (indicate, how far the dataset can be processed by the used system”)

1.4 failure rate (indicate the degree of probability of a failure of a dataset within an assumed period)

1.5 .............................

2 up-to-dateness

(or: currentness) (the dimension of conformity of information to the time-depending conceptual reality)

2.1 last update (in case of creation, modification, deletion or unchanged use) (Aalders 2002)

2.2 rate of change (how the conceptual reality is changing)

2.3 comparison between rate of update and rate of change(comparison of how the dataset is changing and how the conceptual reality is changing)

2.4 temporal lapse (giving the average time period between the change in the real world and the updating of the database)

2.5 ……………………………………….

3 ........................................................


is very important

is less important

1 2 3 4 5

Integrity (or: fitness of use) (These characteristics include processing and management of data in information systems particularly).

4 completeness (presence and absence of features, their attributes and relationships) (ISO 19113)

4.1 commission (excess data present in a dataset) (ISO 19113)

4.2 omission (data absent from a dataset (ISO 19113)

4.3 feature completeness (if or to what degree all features by the data description are really present in the dataset) (Brassel et al. 1995)

4.4 attribute completeness (if or to what degree all relevant attributes by the data description are really present in the dataset) (Brassel et al. 1995)

4.5 ..................................................................

5 logical consistency (degree of adherence to logical rules of data structure, attribution and relationships) (ISO 19113)

5.1 geometric consistency (adherence to geometric specification) (DIN ENV 12656)

5.2 topological consistency (correctness of the explicitly encoded topological characteristics of a dataset) set) (ISO 19113)

5.3 thematic consistency (adherence to semantic specification) (DIN ENV 12656)

5.4 conceptual consistency (adherence to rules of the conceptual schema) (ISO 19113)

5.5 domain consistency (adherence of values to the value domains) (ISO 19113)

5.6 format consistency (degree to which data is stored in accordance with the physical structure of the dataset) (ISO 19113)

5.7 ............................................................

6 correctness (the extent of accordance of information to conceptual reality)

6.1 non-quantitative attribute correctness (correctness of non-quantitative attributes) (ISO 19113)

6.2 classification correctness (Comparison of the classes assigned to features or their attributes to a universe of discourse) (ISO 19113)

6.3 ................................................

7 ................................................


is very important

Is less important

1 2 3 4 5

Accuracy (data and Information are results of measurements or interpretations. These measurements and interpretations can be done only with a bounded resolution. This phenomenon can represented by the characteristics of accuracy)

8 positional accuracy (accuracy of position of features) (ISO 19113) or

metric accuracy (accuracy of metric of features)

8.1 relative or internal accuracy (accuracy of the positions of occurrences of entities relative to each other (in both the horizontal (x,y) and vertical (z) dimensions) (Aalders 2002)

8.2 absolute or external accuracy (accuracy measured (in both the horizontal (x,y) and vertical (z) dimensions) against the spatial reference system) (Aalders 2002)

8.3 ........................................

9 attribute accuracy (this refers to the accuracy of continuous (also called scalar or quantitative) and discrete (also called qualitative or nominal) values in a dataset) (Aalders 2002) or

thematic accuracy (ISO 19113)

9.1 quantitative attribute accuracy (accuracy of quantitative attributes) (ISO 19113)

9.2 qualitative attribute accuracy (accuracy of qualitative attributes)

9.3 .........................................................................

10 temporal accuracy (accuracy of the temporal attributes and temporal relationships of features) (ISO 19113)

10.1 accuracy of a time measurement (correctness of the temporal references of an item - reporting of error in time measurement) (ISO 19113)

10.2 temporal validity (validity of data with respect to time) (ISO 19113)

10.3 temporal consistency (correctness of ordered events or sequences, if reported) (ISO 19113)

10.4 ...........................................................

11 …………………………………………………………


is very important

Is less important

1 2 3 4 5

further phenomenon regarding quality

12 lineage (describes the history of a geographic dataset) (DIN – ENV 12656)

13 ........................................

14 ........................................

15 ........................................

comments:

......................................………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………… ………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………

Thank you very much for cooperation ! ☺

Sources: Aalders, Henri J.G.L (2002): The Registration of Quality in a GIS. – In: Wenzhong Shi; Fisher, P. F. ; Goodchild ; M. F. (Eds.): Spatial Data Quality. Taylor & Francis. London

Brassel, Kurt et al. (1995): Completeness. - In: Guptill, Stephen C.; Morrison, Joel L. (Eds.): Elements of Spatial Data Quality. Elsevier. Oxford.

DIN - Deutsches Institut für Normung e.V. (1998): DIN V ENV 12656 Geoinformation Datenbeschreibung Qualität. Deutsche Fassung ENV 12656:1998.

ISO - International Organization for Standardization (2002): ISO 19113. Geographic information – quality principles.


Annexe C: Literature AALDERS, HENRI J.G.L (2002): The Registration of Quality in a GIS. In: Wenzhong Shi; Fisher, P. F.; Goodchild ; M. F. (Eds.): Spatial Data Quality. Taylor & Francis; London

ADV - ARBEITSGEMEINSCHAFT DER VERMESSUNGSVERWALTUNGEN DER LÄNDER DER BUNDESREPUBLIK DEUTSCHLAND (2004): Dokumentation zur Modellierung der Geoinformationen des amtlichen Vermessungswesens (GeoInfoDok); Version 3.0; Bonn (http://www.adv-online.de/)

BRASSEL, KURT ET AL. (1995): Completeness. In: Guptill, Stephen C.; Morrison, Joel L. (Eds.): Elements of Spatial Data Quality. Elsevier; Oxford.

BUSCH, A., WILLRICH, F. (2002): Quality Management of ATKIS Data. In: OEEPE/ISPRS Joint Workshop on Spatial Data Quality Management, 21-22 March 2002, Istanbul

CEN TC 278 (1995): Geographic Data Files. Draft of a European Standard (http://www.ertico.com/links/gdf/gdfdoc/gdfdoc.htm)

CEN – EUROPEAN COMMITTEE FOR STANDARDIZATION (1998): DD - ENV 12656. Geographic information - data description – quality. Brussels

CEN – EUROPEAN COMMITTEE FOR STANDARDIZATION (2000): EN - ISO 9000. Quality management systems – Fundamentals and vocabulary (ISO 9000:2000). Brussels

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Documents

D2.2 Quality Frame Report · The ISO 19100-series were prepared by Technical Committee ISO/TC211, Geographic information / Geomatics. For the quality of geographic data are especially