In a method of generating a signal for test in a memory device configured to output a multi-level signal, an operation mode is set to a first test mode. During the first test mode, first data bits included in a plurality of test data are arranged based on a first scheme. Each of the plurality of test data includes two or more data bits. During the first test mode, a first test result signal having two voltage levels is generated based on the first data bits according to the first scheme. The operation mode is set to a second test mode during which second data bits included in the plurality of test data are arranged based on a second scheme. During the second test mode, a second test result signal having the two voltage levels is generated based on the second data bits according to the second scheme.