In our context, we have a vectors <math>(a,b)</math> of locations, not a scalar for each point. This changes the math[https://online.stat.psu.edu/stat505/lesson/8/8.2], as well as the ultimate 'estimator'[https://online.stat.psu.edu/stat505/lesson/8/8.3] that we might use.
Specifically, <math>Y_{ij}</math> is a vector: <math>\boldmathmathbf{Y_{ij}} = \begin{pmatrix} Y_{ija} \\ Y_{ijb}\end{pmatrix}</math>, as are the sample mean <math>\begin{pmatrix} \bar{Y}_{i\cdot a}\\ \bar{Y}_{i\cdot b} \end{pmatrix}</math> and the grand mean <math>\begin{pmatrix} \bar{Y}_{a}\\ \bar{Y}_{b} \end{pmatrix}</math>
====The Heuristic Method Justification====