sampling frame
... that proper design of a sampling frame can be crucial in statistical research?
... that proper design of a <b id="mwEAo"><a href="./Sampling_frame" id="mwEAs" rel="mw:WikiLink" title="Sampling frame">sampling frame</a></b> can be crucial in <a href="./Statistics" id="mwEAw" rel="mw:WikiLink" title="Statistics">statistical</a> <a href="./Research" id="mwEA0" rel="mw:WikiLink" title="Research">research</a>?