The input-method tag seems to be used for a confusing mish-mash of topics.
Everything from international keyboard types and IMEs, to how to make a Submit button appear on web page form or how to attach a guitar to your phone's audio socket or how to use a joystick, these are all on the first page for the tag.
It seems to me that there's no real commonality between all those questions.
From just hearing the tag name I'd assume it was meant to refer to IMEs (Input Method Editors, usually a way to input complex characters for languages like Chinese on a keyboard with a limited number of buttons, also used to switch between different keyboard types). But I can see that most of the other questions also involve a form of input to the device.