At the top of this graphic is the formula for calculating the alignment index, 'alignment equals one minus the absolute value of the matrix of assessment cell proportion minus the matrix of standards cell proportion, summed across all the cells divided by two.' Below this formula are three matrices. The first matrix is the standards matrix containing the following numbers by row: row one, point two, point two, and point one; row two, point one, point one, and point one; row three, point zero, point two, and point zero. The second matrix is the assessment matrix containing the following numbers by row: row one, point two, point zero, and point one; row two, point one, point two, and point zero; and row three, point one, point two, and point one. The third matrix is the absolute difference in matrices containing the following numbers by row: row one, point zero, point two, and point zero; row two, point zero, point one, and point one; and row three point one, point zero, and point one. The three matrices are set up as an equation that reads 'standards matrix minus assessment matrix equals absolute difference in matrices.