In a small bowl whisk together honey, lemon juice, and gingerroot until combined. Add oil in a slow stream, whisking until emulsified, and season with salt and pepper. Thinly slice scallions diagonally and cut carrot into 1-inch-long thin julienne strips.
In a 4-quart kettle bring 3 quarts salted water to a boil. Shell and devein shrimp. Simmer shrimp until just cooked through, about 1‚ minutes. With a slotted spoon transfer shrimp to a plate. Return water to a boil and add noodles. Cook noodles until just tender, about 3 minutes. In a colander rinse noodles under cold water to stop cooking and drain well. With scissors cut noodles into 4-inch lengths.
Pit and peel avocado and cut into 1/4-inch dice. In a large bowl gently toss together shrimp, noodles, vegetables, dressing, and salt and pepper to taste.
