Study on Deciding Standardized Elements for Scientific Data in the Field of Ocean Observation 1

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1 Study on Deciding Standardized Elements for Scientific Data in the Field of Ocean Observation 1 Suntae Kim 1, Kyongseok Park 1, Sanghwan Lee 1, Hanmin Jung 1, Yong Kim 2, Tae-Young Lee 2 1Korea Institute of Science and Technology Information, 245 Daehangno, Yuseong-gu, Daejeon, , South Korea {stkim, gspark, jhm, sanglee}@kisti.re.kr 2Chonbuk National University, 567 Baekje-daero, deokjin-gu, Jeonju-si, Jeollabuk-do South Korea {yk9118, taehyun}@jbnu.ac.kr Abstract. The goal of this study is to develop standardized elements for managing and utilizing the scientific data in the ocean observation field. To construct standardized elements, data attributes and search factors were analyzed from the raw data which were collected from marine physics, marine chemistry, marine biology, marine geology area and the services of the KODC, NFRDI, KHOA were analyzed to derive metadata elements for retrieval. Metadata schemas such as DataCite, DC, OECD, DIF, MODS and the technologies of web services were analyzed. The scholarly information services and terms were also analyzed. The standard elements derived from the analysis of the items were categorized by using the 'Record Management Metadata Standard' which was made by National Archives of Korea and the lower elements thereof were established. The standard elements were surveyed by the 22 experts. To describe the ocean observation data, the 21 higher elements and the 173 lower elements were selected. Keywords: Scientific Data, Observation Data, Ocean Observation Data, Metadata 1 Introduction It is necessary to constitute a system for managing, sharing and reusing ocean data, but each of the various international organizations, international cooperative programs and data centers involved in ocean is making its own metadata standard for ocean data so as to achieve its own goals. As a result, there is no unified international standard. 1. This essay is a modified version and summary of a graduate school thesis, Chonbuk National University (February 2, 2012). 386

2 In Korea, while various government branches such as KORDI(Korea Ocean Research & Development Institute), KHOA(Korea Hydrographic and Oceanographic Administration), NFRDI(National Fisheries Research & Development Institute) and the oceanologic departments in universities all produce their own data related to oceanic research there is poor standardization and system interconnectivity [2]. Therefore, this study aims to determine standardized elements required for managing and using ocean observation data. 2 Related Work Fiolek (2009) compared and analyzed the metadata schema used by the NCL (NOAA Central Library) Network, the NODC (National Occanographic Data Center), and the NCDDC (National Coastal Data Development Center). Kojima (2010) proposed an extended information search system based on the index of each data type for searching the metadata included in the large observation data-satellite photos. Peroni and Shotton (2011) are studying the method of mapping the DataCite elements to the terminology recognized in the field of ontology. Lee (2007), Ahn (2005, 2008) and STISC (2006) studied metadata standards for earth observation data, bio-diversity data, experiments, measurements, and simulation data sets. The aforementioned studies aimed to present schemes for standardizing observation metadata, but only targeted some of the existing metadata standards. Therefore, it is necessary to study how to determine standardized elements comprehensively taking into consideration: analysis of ocean observation data and the metadata standards to be studied, web service query language, scientific data services, related technology terminology, metadata standards for records, and review by experts. 3 Analysis of ocean observation data By analyzing both raw data and retrieval service data in the fields of marine physics, marine chemistry, marine biology and marine geology we derived the following characteristics. First, raw data in each field may or may not contain contextual information related to the observation. Second, the term observation elements means the elements to be observed through observation. When different observation methods are used for different observation purposes at one observation station or even a plurality of observation stations, the resulting contents of observed data are different. Diversified types of raw data are created depending on the various observation instruments used. Third, we found essential elements to be: observation stations and observation station identifiers, spatial information (latitude, longitude), and depth information with respect to the characteristics of ocean observations. Fourth, key elements such as observation instruments, observation methods, projects for creating observation data and the information of the observatory, were critical in terms of managing and using observation data. Fifth, since the observation elements are described in the raw data depending on the purpose of observation, they are used for limiting the items of retrieval results rather than for retrieval contacts. Sixth, there are 387

3 different metadata elements for describing raw data depending on the type of observation data. 4 Analysis of standardized elements The standardized metadata elements were analysed through the following 4 steps. In step 1, the key metadata elements of DC were analysed on the basis of the metadata elements of the DataCite Consortium. The OECD metadata elements developed to cite the data sets and tables were also analyzed. Investigation was also made into DIF metadata elements in the field of earth observation and MODS which is a metadata standard in the field of library and information science. In step 2, analysis was made of the metatag of Z39.88, context sets registered in CQL, OAI-PMH, RSS standard protocols and messages. In step 3, investigation was made into Scopus of the Elsevier Press, the Web of Science of ISI, and NDSL of KISTI. In step 4, analysis was made of terminology of DataCite and DCMI so as to derive metadata elements for describing the relationship of the data. As a result, 27 metadata elements and 15 index field elements were derived through the above analysis process. 5 Pre-design of standardized elements 5.1 Comparison and review of higher elements for record management metadata The metadata elements derived in this study were examined on the basis of Standard for record management metadata established by the National Archives of Korea in order to manage and distribute records. The derived metadata elements were categorized and the lower elements of the elements were derived. As a result of examining the different categorization, 13 elements exactly form a 1:1 relationship including the title among 21 higher elements of Standard for record management metadata. The "Preservation, Retention and Management History" was excluded from the lower element review items because it corresponds to metadata for preservation. 5.2 Evaluation of survey for pre-design The Pre-design of metadata for describing scientific data in the field of ocean observation (provisional) proposed in this study was examined through interviews and questionnaires. In particular, questionnaires were used for experts specialized in observation and experts specialized in academic information distribution. The number of questionnaire respondent (evaluators) samples for qualitative study was 22 as 388

4 suggested in the basis of the research by Mason on sample size in studies utilizing interviews [3]. The experts proposed 31 metadata elements as essential elements as shown in Table 1. Four elements that were proposed included the gridded data as elements for the structure category. Twenty-one elements that were proposed included the data quality elements as elements for the contents category. Five elements that were proposed included the depositor element as the element for the Context category and the data access type element was proposed as the record management category. Twenty six new elements were added including the Gridded element. The analysis of experts opinion on the performance of each element presented in the prior-design (provisional) of metadata suggested changing the performance of 39 elements among the 114 elements. It was considered as an essential element if the average of the essential agreement scores of the experts about the metadata elements was not smaller than 4.5. It was considered as an unnecessary element if smaller than 2.5. The Owner which was Discretionary in the pre-design (provisional) among the metadata elements was changed to Essential in the final Design among the metadata elements. Performance of 32 metadata elements was changed from Discretionary to 'Essential if relevant', including the metadata type name field. Performance of six metadata elements was changed from Essential to Essential if relevant, including the Physical storage of scientific data field. The Personal ID element was changed from Essential if relevant to Discretionary. Five metadata elements were changed from Essential if relevant to Essential, including the metadata submitter name. The experts suggested Essential if relevant for the actor type, but Essential was applied because it had essential elements in the lower element. Table 1. List of metadata elements proposed by experts Category Type Element Name Structure category New Gridded Structure category New Point Structure category New Data Unit Structure category New Data Viewer Contents category Existing Data Quality Contents category New Data Item Contents category New Model Name Contents category Existing Instrument Name Contents category New Instrument Version Contents category New Observation Location Contents category New Time Interval Contents category New Depth Contents category New Spatial Resolution Contents category New Vertical Resolution Contents category New Deflection Angle Contents category Existing Observation DateTime Contents category Existing Beginning DateTime Contents category Existing Ending DateTime Contents category New Beginning Location Contents category New Ending Location Contents category New Deposit Result 389

5 Contents category New Project ID Contents category New Observation Objective Contents category New Observation Method Contents category New Abstract Context category New IsReanalyzedBy Context category New Reanalyze 6 Determining standardized metadata elements in the field of ocean observation 6.1 Principle of determining standardized elements The following describes the principle of designing standardized metadata elements. (1) DC, which is globally recognized as the set of common elements, in the metadata form design, was included to reflect the standardized elements extended as other elements in DCMI and the standard review elements [4]. (2) All of the elements derived by direct analysis of ocean observation data were reflected in standardized metadata elements. (3) Relevant rules were reflected for the element corresponding to the first development principle in the elements further proposed in the questionnaires for the experts. New elements were reflected for other elements. (4) It is necessary to develop metadata elements of the meta-metadata type for collecting various metadata in the field of ocean observation and providing integrated retrieval. To this end, elements were added in consideration of characteristics of possession of collected metadata and positional characteristics of the data. (5) Both researcher-driven retrieval and system-driven retrieval were accepted. Sixth, some of the representative elements were renamed for improved readability of fields. 6.2 Determing of standardized elements The following section shows the final standardized metadata elements comprised of 21 higher elements and 173 lower elements in this study. Figure 1 shows the process of deriving standardized metadata elements in this study. The derived elements were described to include: category, higher element name, higher element repetition, performance of higher elements, lower element name, lower element performance, lower element repetition, encoding scheme, and were divided by blanks. The following shows the list of some of the derived metadata elements. The entire elements can be viewed on the website Structure Type x 2 DataTypeCategory 1 x Structure Type x 2 DataTypeCode 2 x Structure Type x 2 DataType 2 x Structure Format x 2 DataUnit 2 x Structure Format x 2 DataViewer 2 x Structure Format x 2 DataVersion 2 x 390

6 Structure Extent x 2 Size 2 x Structure Extent x 2 Count 2 x Context Identifiers x 2 Identifier 2 x URI Context Identifiers x 2 AlternateIdentifier 3 o URI Context Titles x 1 Title 1 x Context Titles x 1 UniformTitle 3 x Context Description x 1 SpatialResolution 2 x Context Description x 1 VerticalResolution 2 x Context Description x 1 DataItem 1 o Context Description x 1 GridedFlag 2 x Context Description x 1 PointFlag 2 x Context Subject ES05 Context Date x 1 CreationDateTime 1 x ES06 Context Date x 1 LastReviewDateTime 3x ES06 Context //Encoding Scheme ES01 ES03 ES06 ES07 Deriving metadata elements in the hybrid manner Review record management standards Add elements after questionnaire survey Other added elements Analyze marine observation data 115 metadata elements (11 higher elements, 104 lower 27 index fields 38 metadata elements (8 higher elements, 30 lower 26 metadata elements (0 higher element, 26 lower 6 metadata elements (2 higher elements, 4 lower 9 metadata elements (0 higher element, 9 lower Deriving metadata elements in the hybrid manner (Derive 88 metadata elements 28 index fields) Compare them with the record management standards of National Archives of Korea Review by experts and proposal of elements 194 standardized metadata elements 21 higher elements 173 lower elements Fig 1. Deriving standardized metadata elements 391

7 7 Conclusion This study is different from previous studies because we propose a new method for selecting standardized metadata elements. That is, previous studies were carried out by investigating characteristics of target contents for deriving metadata elements and then reviewing some of the metadata standards to extend insufficient metadata elements. This study proposes a new method for studying how to derive hybrid metadata elements by reviewing metadata elements for records, evaluating predesign elements through expert questionnaires and thus deriving new elements. It is expected that the standardized metadata elements proposed in this study will contribute to managing and using metadata in the field of ocean observation. This study may also be useful in other fields that deal with large data sets by proposing a method for reviewing and selecting standardized metadata elements. References 1. Suntae Kim. A Study onextraction and Design of Standardized Elements on Metadata for Ocean Observational Data. Chonbuk National University (2012) 2. KISTI. A preliminary study on establishing National Center for sharing and converging Scientific Data. Daejeon (2012) 3. Mason, Mark. Sample Size and Saturation in PhD Studies Using Qualitative Interviews. Forum Qualitative Sozialforschung / Forum: Qualitative Social Research, Vol.11, No.3 (2010) 4. Jung-Yeoun Lee, Jung-Min Kim, Suk-Doo Choi, Lee-Kyum Kim. AStudtyon Design and Analysis of Metadata and Ontology based on Humanities and Social Sciences. Journal of the Korean society for library. Vol.41, No.2 (2007) 5. Anna Fiolek, Susan Gottfried, Stacy Ladnier, Sharon Mesick. Mapping, Cross-walking, Converting and Exchanging Oceanographic Metadata Information in Video Data Management System. MTS (2009) 6. Kojima, I., Masahiro Kimoto and Akiyoshi Matono. OGC catalog service for heterogeneous earth observation metadata using extensible search indices. Proceedings of the 6th Workshop on Geographic Information Retrieval (2010) 7. Bu-young Ahn, Hee-hyung Cho, Sung-soo Ahn, Hyung-seon Park. Design of Metadata Schema for Biodiversity Data Exchange. The Korean Institute of Information Scientists and Engineers. Vol.32, No.2, pp (2005) 8. Bu-young Ahn, Jeong-Min Han, Oh-Kyoung Kwon, Min-Su Joh. A Study on Design of Metadata for Global Earth Observation Data. Journal of Information Management. Vol.39, No.2, pp (2008) 9. STISC. Standard : Metadata on the Information of Datasets in Science and Technology (2006) 10. Hye-Young Lee, Seung-Jin Kwak. A Study on Metadata for Sharing the Information of Earth Observation. Korean society for library and information science. Vol.41, No.2, pp (2007) 392