In the original publication of this article (Yanagisawa & Webb, Reference Yanagisawa and Webb2021), the presentation of the second incidental vocabulary learning (IVL) formula, the incidental vocabulary learning formula of activities for retention, contained an incorrect number. The number “15.3” in the second-to-last line of the formula should be “11.5.” The full correct formula appears below:

$$ {\displaystyle \begin{array}{l} The\hskip0.5em incidental\hskip0.5em vocabulary\hskip0.5em learning\hskip0.5em for mula\hskip0.5em of\hskip0.5em activities\hskip0.5em for\hskip0.5em retention\\ {}\begin{array}{ll}& =\hskip0.5em \left[ Need\hskip0.5em \left( absent\hskip0.5em :\hskip0.5em 0\hskip0.5em or\hskip0.5em present\hskip0.5em :\hskip0.5em 1\right)\hskip0.5em \times \hskip0.5em 13.8\right]\\ {}& \hskip1.5em +\hskip0.5em \left[ Search\hskip0.5em \left(0\hskip0.5em or\hskip0.5em 1\right)\hskip0.5em \times \hskip0.5em -5.1\right]\\ {}& \hskip1.5em +\hskip0.5em \left[ Evaluation\hskip0.5em \left(0\hskip0.5em or\hskip0.5em 1\right)\hskip0.5em \times \hskip0.5em 9.1\right]\\ {}& \hskip1.5em +\hskip0.5em \left[ Sentence\hbox{-} level\hskip0.5em varied\hskip0.5em use\hskip0.5em \left(0\hskip0.5em or\hskip0.5em 1\right)\hskip0.5em \times \hskip0.5em 11.5\right]\\ {}& \hskip1.5em +\hskip0.5em \left[ Composition\hbox{-} level\hskip0.5em varied\hskip0.5em use\hskip0.5em \left(0\hskip0.5em or\hskip0.5em 1\right)\hskip0.5em \times \hskip0.5em 21.0\right]\end{array}\end{array}} $$

The original article has been updated. The publisher apologizes for this error.