It is demonstrated that any realistic model of quintessence should be based on Supergravity since , when the scalar field is on tracks today , Q \approx m _ { Pl } .
This improves the agreement between theoretical predictions and the current observations .
In particular , a generic property is that ratio \omega _ { Q } \equiv p _ { Q } / \rho _ { Q } is pushed towards -1 .
A string-inspired model is proposed where the potential is given by V ( Q ) = \frac { \Lambda ^ { 4 + \alpha } } { Q ^ { \alpha } } e ^ { \frac { \kappa } { 2 } Q ^ { 2 } } .
The model predicts \omega _ { Q } \approx - 0.82 , a value less that one sigma from the current likehood value .