Fig. 2. Annotated Excerpt from Human-Human Spoken Tutoring Corpus


PHYSICS PROBLEM (TYPED): The sun pulls on the earth with the force of gravity and causes the earth
to move in orbit around the sun. Does the earth pull equally on the sun? Defend your answer.
  
STUDENT ESSAY (TYPED): No. Both objects apply a force on the other. The sun applies more force because it is causing the earth to have more acceleration.
 
DIALOGUE (SPOKEN): ... excerpt at 4.3 minutes into dialogue ... 
(play entire dialogue: wav  mp3)
 
(wav  mp3TUTOR5: The only thing asked is about the force, whether the force of earth pulls equally on the sun or not. That's the only question.
                                                                                                          
(wav  mp3STUDENT5: Well I think it does but I don't know why. I do-don't I- do they move in the same direction? I do-don't (NEGATIVE)
 
(wav  mp3TUTOR6: You see, against- you see, they don't have to move. If a force acts on a body-
 
(wav  mp3STUDENT6: it- (POSITIVE)
 
(wav  mp3TUTOR7: it does not mean that uh uh I mean it will um-
 
(wav  mp3STUDENT7: If two forces um apply- if two forces react on each other then the force is equal. It's the Newtons third law. (POSITIVE)
 
(wav  mp3TUTOR8: Um you see the uh- actually in this case the motion is there but it is a little more complicated motion. This is orbital motion.
 
(wav  mp3STUDENT8: mm-hm (NEUTRAL)



Fig. 3. Annotated Excerpt from Human-Computer Spoken Tutoring Corpus

PHYSICS PROBLEM (TYPED): An airplane flying horizontally drops a packet when it is directly above the center of a swimming pool.  Does the packet hit that spot? Explain.
 
STUDENT ESSAY (TYPED): No, the packet is still being affected by the force of the airplane flying horizontally, so the packet will also move horizontally, slightly as it falls downward. This will cause the packet to hit a spot that is no directly in the center of the pool.
 
DIALOGUE (SPOKEN): ... excerpt at 18.6 minutes into dialogue ...
(play entire dialogue: wav  mp3)
 
(wav  mp3ITSPOKE22: Ok, let's consider how forces in the vertical direction affect the motion of a body in a horizontal direction in a different scenario. Say an apple falls from a tree. What force(s) are acting on the apple as it falls?
 
(wav  mp3STUDENT19: gravity (ASR: gravity) (NEGATIVE)
 
(wav  mp3ITSPOKE23: Yeah.  Are there any other forces acting on the apple as it falls?
 
(wav  mp3STUDENT20: no (ASR: no) (NEGATIVE)
                                                                                                       
(wav  mp3ITSPOKE24: Fine.  The only force acting on the apple as it falls to the earth is the earth's gravitational force. In which direction does gravitational force act?
 
(wav  mp3STUDENT21: down (ASR: down) (POSITIVE)
 
(wav  mp3ITSPOKE25: Yep.  Therefore, what is the magnitude of this gravitational force in the horizontal direction?
 
(wav  mp3STUDENT22: in the direction of the airplane (ASR: it met the direction that of the the airplane moon) (NEUTRAL)