title: Ancova with multiple independent variables and 1 categorical variable
body: <p>I am new to running Ancova in R. I am trying to see if my categorical variable (time) is significant in my dependent variable (Sales) while holding all other variables in my model constant.</p>
  
  <pre><code>aov(Sales ~ Price+Merch+ACV+Items+Category+Time, data = PintsT)
  </code></pre>
  
  <p>My question is how are you confident the <code>Pvalues</code> are relevant when holding the other variables constant? Does it automatically assume this using a type 3 analysis?</p>
  
  <p>Also when would you use <code>*</code> instead of <code>+</code> in between the independent variables?</p>