Another researcher then independently analysed half of the data, and the researchers compared their results for consistency to check that the analysis had been done correctly.
Yna dadansoddodd ymchwilydd arall hanner y data yn annibynnol, ac fe gymharodd yr ymchwilwyr eu canlyniadau am gysondeb i wirio bod y dadansoddiad wedi'i wneud yn gywir.