Sometimes it is. It depends on how the pattern is worded. If it says something like 'yf, k2tog (or sl 1 k1, psso), k3' then it is. If it says 'yf, slip 1, yb/yarn back, k2' then it's just bringing the yarn to the front of your work to slip the stitch. Which pattern is it, or how does the row read?
sue- knitting heretic