Beamer \institute text size change to small

Question

I am using beamer with the \institute command.

I have several institutes and just want to change the font size of the institutes and not the whole document. I would like the institutes to be much smaller than the rest of the document.

Here is my code, but maybe I'm lost. Thanks for any input as I am new to beamer and LaTeX.

\institute[University of] {size=\fontsize{9pt}{10pt}\selectfont University of Utah}%   
{
  \inst{1}%
  Department of Electrical and Computer Engineering\\
  University of
  \and
  \inst{2}%
  Department of Chemistry\\
  University of
  \and
  \inst{3}%
  Department of\\
  University of
  \and
  \inst{4}%
  Department of \\
  University of
  ~ \\
  \pgfuseimage{medallion}
}

Answer 1

You can change the font size of beamer elements using \setbeamerfont{<element>}{<font attributes>}:

\documentclass{beamer}

\setbeamerfont{institute}{size=\tiny}

\institute[University of]{
  \inst{1}%
   Department of Electrical and Computer Engineering\\
   University of
  \and
  \inst{2}%
  Department of Chemistry\\
 University of
   \and
  \inst{3}%
  Department of\\
  University of
  \and
  \inst{4}%
  Department of \\
   University of
  ~ \\
  \pgfuseimage{example-image}
}

\begin{document}
\maketitle
\end{document}

If you want to use absolute font sizes instead of the LaTeX commands \tiny ... \Huge, try something like

\setbeamerfont{institute}{size=\fontsize{7pt}{8pt}}

(\selectfont is not necessary in this context). Also see the beamer manual for more information about \setbeamerfont.