Provided are methods of programming a nonvolatile data storage device including memory blocks sharing a block word line. The methods may include selecting the memory blocks, and the selected memory blocks may include a first memory block that is to be programmed and a second memory block that is to be program-inhibited. The methods may also include applying a program voltage to a selected word line of the first memory block. The methods may further include applying a bipolar prohibition voltage to word lines of the second memory block.