What Does This Channel
Measure?
This channel measures the output voltage of a rating dial or rating
slider. This is often used during experiments to elicit subjective
responses from subjects on how they feel.
E.g., the subject might be asked to indicate with the dial if she feels
negative (turn left), neutral (keep in the middle), or positive (turn
right). This angle of the knob is picked up by a potentiometer (a
variable resistor) and converted to a voltage proportional to the angle
of the dial. The voltage is then recorded continuously.
Editing of rating dial data
The editing is very simple: usually nothing needs to be done. If there
is any electronic artifact in the signal it can be edited out by using
the outlier rectangular option. This also allows setting certain
intervals to missing data (e.g., if a facial video tape reveals that
the subject had fallen asleep), or interpolating between two points.