Since ray OC is the angle bisector of ∠AOB, it divides ∠AOB into two equal angles. Given that the measure of ∠AOB is 74 degrees, we can find the measure of ∠AOC by dividing the measure of ∠AOB by 2.
\[ m∠AOC = \frac{m∠AOB}{2} = \frac{74}{2} = 37 \text{ degrees} \]
Thus, the measurement of ∠AOC is 37 degrees.