How do I work an ssk and ssp instruction?

by Rita Cox
(Rye, England)

I am knitting a scallop edged wrap by Kate Samphier and there is an instruction that isn't clear, it is ssk and ssp, in the explanation it reads slip slip knit and slip slip purl. Does this mean slip two stitches in a knitwise (or purlwise manner). I can't fathom out quite what this means. The pattern can be found in a book called 'Pretty Knits' if you could describe what the instructions means I would be very grateful.