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The text on this page is taken from an equivalent page of the IEHIAS-project.

Triangulation is the process of making repeated estimates of the same phenomena, using different (and independent) methods. Its aim is not to validate any specific method, but to give confidence in the final results (and obtain an indication of their possible uncertainties) by drawing on different approaches.

To be informative, it is essential that the methods used are truly independent – i.e. are based on unrelated principles, data sets and/or systems of analysis. One well-established example of its use is the production of so-called ensemble forecasts of the weather, made by running different meteorological models and then pooling the results.

Triangulation has special value in relation to screening, for the simple and rapid methods of assessment that have to be employed for this purpose often have limited credibility, and may be subject to significant errors. Examples might therefore include:

  • Using a range of different survey methods (e.g. focus groups, questionnaires, delphi studies) to elicit expert opinions on potential health impacts of a policy;
  • Using expert elicitation and extrapolation techniques to estimate potential impacts of a climate change scenario;
  • Using different proxies (e.g. based on distance from source, source intensity) to estimate exposure distributions across a study population.

The estimates made by these various methods might then be compared, to indicate the likely range of uncertainty inherent in the preferred estimate, or they might be averaged to provide a pooled estimate. In the latter case, it may be appropriate to weight the results, to reflect their relative uncertainties, and it is certainly likely to be helpful to report the range of values obtained (or some measure of their variability).

See also

Integrated Environmental Health Impact Assessment System
IEHIAS is a website developed by two large EU-funded projects Intarese and Heimtsa. The content from the original website was moved to Opasnet.
Topic Pages

Boundaries · Population: age+sex 100m LAU2 Totals Age and gender · ExpoPlatform · Agriculture emissions · Climate · Soil: Degredation · Atlases: Geochemical Urban · SoDa · PVGIS · CORINE 2000 · Biomarkers: AP As BPA BFRs Cd Dioxins DBPs Fluorinated surfactants Pb Organochlorine insecticides OPs Parabens Phthalates PAHs PCBs · Health: Effects Statistics · CARE · IRTAD · Functions: Impact Exposure-response · Monetary values · Morbidity · Mortality: Database

Examples and case studies Defining question: Agriculture Waste Water · Defining stakeholders: Agriculture Waste Water · Engaging stakeholders: Water · Scenarios: Agriculture Crop CAP Crop allocation Energy crop · Scenario examples: Transport Waste SRES-population UVR and Cancer
Models and methods Ind. select · Mindmap · Diagr. tools · Scen. constr. · Focal sum · Land use · Visual. toolbox · SIENA: Simulator Data Description · Mass balance · Matrix · Princ. comp. · ADMS · CAR · CHIMERE · EcoSenseWeb · H2O Quality · EMF loss · Geomorf · UVR models · INDEX · RISK IAQ · CalTOX · PANGEA · dynamiCROP · IndusChemFate · Transport · PBPK Cd · PBTK dioxin · Exp. Response · Impact calc. · Aguila · Protocol elic. · Info value · DST metadata · E & H: Monitoring Frameworks · Integrated monitoring: Concepts Framework Methods Needs
Listings Health impacts of agricultural land use change · Health impacts of regulative policies on use of DBP in consumer products
Guidance System
The concept
Issue framing Formulating scenarios · Scenarios: Prescriptive Descriptive Predictive Probabilistic · Scoping · Building a conceptual model · Causal chain · Other frameworks · Selecting indicators
Design Learning · Accuracy · Complex exposures · Matching exposure and health · Info needs · Vulnerable groups · Values · Variation · Location · Resolution · Zone design · Timeframes · Justice · Screening · Estimation · Elicitation · Delphi · Extrapolation · Transferring results · Temporal extrapolation · Spatial extrapolation · Triangulation · Rapid modelling · Intake fraction · iF reading · Piloting · Example · Piloting data · Protocol development
Execution Causal chain · Contaminant sources · Disaggregation · Contaminant release · Transport and fate · Source attribution · Multimedia models · Exposure · Exposure modelling · Intake fraction · Exposure-to-intake · Internal dose · Exposure-response · Impact analysis · Monetisation · Monetary values · Uncertainty