A phrase generally used in a political context to rhetorically challenge the validity of the other side's arguments. The phrase has arisen in agricultural trade disputes when a country imposes a sanitary or phytosanitary (SPS) measure that an exporting group claims is an unfair trade barrier because it is "not based on sound science." Often, policymakers or adjudicators are asked to make decisions based, at least in part, on which side's scientific arguments appear to be the most convincing. However, the phrase sound science is not included in public laws or international treaties. Under the Uruguay Round's SPS agreement, countries' SPS measures must be based on scientific principles, and may not be maintained without scientific evidence. However, the agreement does not define "scientific." Under general principles of international law, the interpretation of the term is left to good faith and ordinary "dictionary" definitions. By requiring only that measures be based on scientific principles, as broadly understood and accepted by the scientific community, the agreement, therefore, does not expect those who are adjudicating trade disputes to choose which science is the "sound science."