Presentation on theme: "GLOBAL DEVELOPMENTS OF NATIONAL SPATIAL DATA CLEARINGHOUSES J.W.H.C. CROMPVOETS WAGENINGEN UNIVERSITY, CENTRE FOR GEO-INFORMATION BUDAPEST, GSDI 6 CONFERENCE."— Presentation transcript:
GLOBAL DEVELOPMENTS OF NATIONAL SPATIAL DATA CLEARINGHOUSES J.W.H.C. CROMPVOETS WAGENINGEN UNIVERSITY, CENTRE FOR GEO-INFORMATION BUDAPEST, GSDI 6 CONFERENCE - FROM GLOBAL TO LOCAL WEDNESDAY 18TH SEPTEMBER 2002, 16.00 HOUR STREAM 1 - DEVELOPING SDIs SESSION 3 - sdi case studies (2) - Focus on metadata/clearinghouse
INTRODUCTION First study about national clearinghouse developments around the world on a systematic, periodical way Main Objective(s) Study: Progress description based on several characteristics Spatial Distribution Similarities and differences between national clearinghouses Sub-objectives (Not done) Legal, Economical, Technical Cultural and Institutional Impact Analyses
Step 1. Inventory of existing national clearinghouses Internet browse, Literature, Contact Experts and Webmasters Step 2. Measurement characteristics of national clearinghouses (± each ½ year) Selection characteristics based on following criteria: - Ease of measurement - Objectivity - Use/Content/Management Main data sources: clearinghouse sites and/or numerous webmaster contacts Start Web Survey: March 2000 Other Survey months: November 2000, March 2001, November 2001, March 2002 WEB SURVEY METHODOLOGY I
Selected 12 Characteristics are: Year of first national implementation Number of data suppliers Type of data accessibility Meta-data standard used Number of datasets Time most recently produced dataset Number of web references (AltaVista and Google) Monthly number of visitors Frequency of web updates Languages used Use of maps for searching Registration-only access WEB SURVEY METHODOLOGY II
SPATIAL DISTRIBUTION OF NAT. CLEARINGHOUSES (Dec. 2001) Main ‘Hotspots’: American continent, Europe (except Eastern-Europe), Australia, South-East Asia and South-Africa ‘Holes’: Africa and Middle-East
NUMBER OF DATA SUPPLIERS Trend ‘Average’: Stabilising March 2002; ‘Average’ 52 data suppliers (Standard Deviation: 238) Trend ‘Median’: Decrease Maximum number (March 2002: 1826 (Canada)
TYPE OF DATA ACCESSIBILITY Trend ‘Abstract’: Decrease Trend ‘Metadata’: Increase Trend ‘Data”: Stabilising 2002 March; Only 8 direct access to data!
META-DATA STANDARD USED Trend CEN: Stable Trend FGDC: High increase (most popular) 10 countries/clearinghouses: Projects to apply ISO 19115 (March 2002)
NUMBER OF DATA SETS Trend ‘Average’: Decrease! March 2002; Average: 3653 Trend ‘Median’: Decrease! March 2002; Median: 74! Trend ‘Summed’: Increase March 2002; FGDC-clearinghouse ± 135 000 data sets descriptions All 24 European clearinghouses together ± 10 000 data sets
MOST RECENTLY PRODUCED DATASET Slight increase of average duration between date of survey and date of most recently produced dataset Average (March 2002): 29 months Minimum (March 2002): 1 month Maximum (March 2002): 261 months
NUMBER OF WEB REFERENCES Link Popularity of national clearinghouses is high! Excellent source of consistent and targeted web traffic. AltaVista trend ‘Average’ and ‘Median’: Actual Decrease March 2002; Average: 252, Standard Deviation: 637! Median: 54 Google trend ‘Average’ and ‘Median’: High Increase March 2002; Average: 251, Standard Deviation: 488, Median: 94
MONTHLY NUMBER OF VISITORS Trend ‘Average’: Stabilising (very low increase) March 2002; Average: 5876, Standard Deviation: 13700 Trend ‘Median’: Stabilising March 2002; Median: 1280 Most visited are: US, Portugal and Slovenia No actual increase in number visitors!
FREQUENCY OF WEB UPDATES Trend ‘Average’: Fluctuating March 2002; Average: 190 (High!) Trend ‘Median’: Increasing! March 2002; Median: 27 (Low!) March 2002; Clearinghouses updated < 1 day: 11 March 2002; Clearinghouses updated > 100 days: 17
LANGUAGES USED Trend: Relatively not many changes March 2002; 34 clearinghouses ‘Search Mechanism’ in English March 2002; 17 in Spanish, 21 Multilingual, 31 Only Home Language
USE OF MAPS FOR SEARCHING Absolute Trend: Increase Relative Trend: Stable March 2002: 22 clearinghouses use maps for searching
REGISTRATION-ONLY ACCESS Absolute Trend: Fluctuating March 2002; 7 clearinghouses Relative Trend: Decrease More clearinghouses are becoming direct accessible!
MAIN CONCLUSIONS I History: Steadily increasing -> More and more national clearinghouses will be established in the future Spatial Distribution: Global Implementation with ‘hotspots’ and ‘holes’ (Several African and Eastern-European countries start projects) Developments Positive: Number of implementations, Metadata access, use of FGDC-standard, Number of ISO 19115 implementations, Summed number of data sets, Number of web references, Registration-only access Negative: Number of Data Suppliers, Direct access to data, Number of data sets per clearinghouse, Most recently produced datasets, Monthly number of visitors, Frequency of web updates
MAIN CONCLUSIONS II SuccessesMany clearinghouses, globally distributed, easier and more access to metadata, well-linked within Internet ConcernsLower interests of data suppliers and users No improvement of content (less number of datasets, less actual data sets, not more direct access to data) Worsening management (lower frequency of web updates) Clearinghouse managers: Keep focused for having a well-managed and content-rich clearinghouse -> Increase use SDI-managers: Remain focused on the core-business of SDI, which is data sharing and data accessibility (clearinghouses!) Differences in content, use and management between clearinghouses are high (especially within Europe).
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