 syntax and quirks. <code>HLMdiag</code> provides diagnostic tools targeting all aspects and levels of hierarchical linear models in a single package. In this update, <code>HLMdiag</code> focuses on usability in its functions. Drawing inspiration from the <code>augment()</code> function in the <code>broom</code> package, the new functions <code><a href="../reference/hlm_resid.default.html">hlm_resid()</a></code>, <code><a href="../reference/hlm_influence.default.html">hlm_influence()</a></code>, and <code><