When characterizing the motion of an object by measuring the location of the object at discrete moments in time, the minimum number of data points needed to estimate the average acceleration of the object are 3 data points.
One data point indicates the location of the object at a given time, while with 2 data points, you can calculate the average speed at the time interval. But with 3 data points you can determine the average acceleration because with 3 data points you can determine the average velocities at two different time intervals.
Therefore, the minimum number of data points you would need to estimate the average acceleration of the object are 3 data points.
ANSWER:
3 data points