Why is linear interpolation and extrapolation not useful in making predictions?

1 Answer
Feb 21, 2015

Linear interpolation is not useful in making predictions because it only suggests data values within an already known range (typical within time). For example, if you knew data values for the years 1980, 1990, 2000, and 2010, interpolation could be used to determine likely values between 1980 and 2010 (that's what interpolation means).

Linear extrapolation is normally not useful in making predictions because so very few time based function are linear in nature and, even in "near future" predictions graphs of values like stock market prices are not smooth.