\setcounter{ExampleCounter}{1}
\paragraph{Observational Study:} \text{}\\
\vspace{0.35in}

\paragraph{Experimental Study:} \text{}\\
\vspace{0.35in}

\subsection{Experimental Study Terms}
\begin{itemize}
\item \textbf{Experimental unit:} \text{}\\
\vspace{0.3in}

\item \textbf{Response:} \text{}\\
\vspace{0.3in}

\item \textbf{Explanatory variable:} \text{}\\
\vspace{0.45in}

\item \textbf{Treatment:} \text{}\\
\vspace{0.35in}

\item \textbf{Lurking variable:} \text{}\\
\vspace{0.3in}

\item \textbf{Control group:} \text{}\\
\vspace{0.3in}

\item \textbf{Placebo:} \text{}\\
\vspace{0.3in}

\item \textbf{Blinding:} \text{}\\
\vfill
\end{itemize}
\pagebreak

\begin{example}{Experimental Design}
Researchers want to investigate whether taking aspirin regularly reduces the risk of heart attack.  Four hundred men between the ages of 50 and 84 are recruited as participants.  The men are divided randomly into two groups: one group will take aspirin, and the other group will take a placebo.  Each man takes one pill each day for three years.  At the end of the study, researchers count the number of men in each group who have had heart attacks.\\

Identify each of the following in this study:\\

\begin{itemize}
\item \textbf{Population:} \\
\vspace{0.4in}

\item \textbf{Sample:} \\
\vspace{0.4in}

\item \textbf{Experimental units:} \\
\vspace{0.4in}

\item \textbf{Control group:} \\
\vspace{0.4in}

\item \textbf{Explanatory variable:} \\
\vspace{0.4in}

\item \textbf{Treatments:} \\
\vspace{0.4in}

\item \textbf{Response variable:} \\
\vspace{0.4in}

\end{itemize}
\end{example}