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Module
4 Global Earth Observation initiatives

United Nations Office of Outer Space Affairs (UNOOSA, http://www.unoosa.org/)
? ? ? Committee on Earth Observation Satellites (CEOS, http://www.ceos.org/)
9-12 December, 2013
Global Earth Observation System of Systems (GEOSS, http://www.epa.gov/geoss/)

3.3 Data compilation

Collection of high-quality data is an essential part of the IEA. You can approach initial decisions about
what data to collect and how to collect it in a couple of different ways. You may begin by conducting
a survey of available data prior to scoping thematic issues for the assessment. Availability of data then
becomes a criterion for selecting data and developing indicators around priority issues. Alternatively,

you may use a more targeted approach, where priority issues and indicators are identified first,
followed by data collection. In this case, if data are not already available, you have four options: (1)
exclude the indicator from your list; (2) define a proxy indicator (and indicator that measures your

issue only indirectly) for which data is available; (3) include the indicator as a theoretical measurement
tool, but point out that data is not available; or if you have time and resources collect primary data,
keeping in mind that in this case time series data will not be available.

Once you have decided on the approach you will use for data collection, you will need to further
develop a plan that includes elements of developing research methods, defining the type of data
needed, and prioritizing which data must be collected. You will also need to specify data sources,

and have a clear sense of the quality of the data. The steps involved in obtaining data and building a
database go hand in hand with developing an assessment report (Figure 6).

Quality of data and precision of measurement are important considerations during data collection.
“Perfect” data are not always necessary or possible, but data quality must be sufficient to satisfy the
IEA’s objectives. Imperfect approximations (proxies) might be used in case no direct data can be

obtained. Well-known examples of this are the use of CO emissions to show long-term climate
2
change risk, or of protected areas to indicate biodiversity. Although different opinions exist as to
whether it is better to have poor data rather than no data at all, the general notion is that IEA is to
be based on the best available, scientifically sound data from widely recognized sources.

36 Monitoring, Data and Indicators