if it is scrap piecing there may not be strips available...and she may be teaching precision...i do alot of strip piecing but i also make projects that i have to cut out lots and lots of little squares for....it depends...and when the (teacher) is working on a project that strip-piecing is good for she probably does it that way...but if she is teaching a scrap class she will use the individual pieces mainly because not everyone starts with yardage when scrap quilting, some of us start with scraps.