Since ray OC is the angle bisector of ∠AOB and ∠AOB measures 74 degrees, we can find the measurement of ∠AOC by dividing the measure of ∠AOB by 2.
\[ m∠AOC = \frac{m∠AOB}{2} = \frac{74\text{ degrees}}{2} = 37\text{ degrees} \]
Therefore, the measure of ∠AOC is 37 degrees.