Measuring filament for extruder calibration

[iras]

The information on calibrating the extruder talks about measuring the amount of filament fed. For example, feed 1mm. Is this talking about measuring the incoming filament (1.75mm) or the amount produced. For example, 1mm of raw filament will produce several times that amount of 0.3mm (for example) extrusion. Which am I measuring? Thanks.

[printbus]

The initial calibration is adjusting the stepper motor to get the proper amount of raw filament movement going into the extruder.