Grease baking dish and spread out the crappie fillets.  Spread a generous amount of Miracle Whip over the fillets.  Then sprinkle dill weed on top.  Melt the butter in a medium sized bowl, then mix the crushed crackers until moist but crumbly, then sprinkle the mix over the fillets.  Bake for 20-25 mins. at 400 degrees.  Then broil for an additional 3 minutes or until top is golden brown.