FASB Codification Assignment

1. Research in the codification and document the authority for using revenue recognition over time or revenue recognition at a point in time for long term contracts. Does the codification express a preference for one method over the other (document where if it does)?
2. Research in the codification and document the authority for using the average cost method for inventory valuation. Does the codification express a preference for use of the periodic or perpetual method for inventory valuation (document the authority if it does)?