<?xml version="1.0" encoding="utf-8"?><!DOCTYPE Zthes SYSTEM "http://zthes.z3950.org/schema/zthes-1.0.dtd">  <Zthes><term><termId>63</termId><termName>Sampling error</termName><termType>TT</termType><termLanguage>en-EN</termLanguage><termVocabulary>SYMSITES</termVocabulary>	<termStatus>active</termStatus>	<termApproval>approved</termApproval>	<termSortkey>Sampling error</termSortkey><termNote label="Scope"><![CDATA[ <p>SYMSITES k-SDSS</p> ]]></termNote><termNote label="Definition"><![CDATA[ <p>The variance among observational units within experimental units; there can be multiple levels of sampling error.</p> ]]></termNote><termNote label="Definition"><![CDATA[ <p>The variance among observational units within experimental units; there can be multiple levels of sampling error.</p> ]]></termNote><termCreatedDate>Sampling error</termCreatedDate><relation><relationType>RT</relationType><termId>54</termId><termName>Observational unit</termName><termType>PT</termType></relation><relation><relationType>RT</relationType><termId>53</termId><termName>Experimental unit</termName><termType>PT</termType></relation></term>  </Zthes>