Hi Lily. Yes, slate goes down just like tile. Thinset mortar etc. You can use a backer like Schluter Ditra if you like... Also remember that slate needs to be sealed, as it is porous. If you seal it before you grout, then you won't stain it all up when you do grout it.
Hey lily bad advice grout gets sealed also . slate is not the same application at all there's a cetain mortar its called beeding mortar, also you do not have to seal slate its rock face like a mountain so it is durable enough to not have to seal it.
Jarred .... actually FirTrader's advice was quite accurate. Yours was wrong.
The method IS the same .... but the requirements are not. Your floor must have much less deflection.
The Slate should be washed, sealed and grouted, (each allowed to dry completely) .... wash and seal again only after the grout has cured for a couple weeks.
Polymer modified thinset or dryset mortar is required as a bond coat. Unless you use Ditra .... then you use an un-modified thinset or dryset mortar as your bond coat.
Understand that some slate tiles need to be leveled as they're set because they're not flat to begin with -- not all, but some. I agree with sealing the tiles as that's what many mfrs recommend -- it's porus stone and may absorb the tints from the grout and compound from the mastic.