id: 06617737
dt: j
an: 2016e.00727
au: Moore, Kevin C.; LaForest, Kevin R.; Kim, Hee Jung
ti: Putting the unit in pre-service secondary teachers’ unit circle.
so: Educ. Stud. Math. 92, No. 2, 221-241 (2016); erratum ibid. 92, No. 2, 243
    (2016).
py: 2016
pu: Springer Netherlands, Dordrecht
la: EN
cc: G60 G40
ut: unit circle; trigonometry; pre-service secondary teachers; measurement;
    teaching experiment; quantitative reasoning
ci: 
li: doi:10.1007/s10649-015-9671-6
ab: Summary: We discuss a teaching experiment that explored two pre-service
    secondary teachers’ meanings for the unit circle. Our analyses
    suggest that the participants’ initial unit circle meanings
    predominantly consisted of calculational strategies for relating a
    given circle to what they called “the unit circle.” These
    strategies did not entail conceiving a circle’s radius as a unit of
    measure. In response, we implemented tasks designed to focus the
    participants’ attention on various measurement ideas including
    conceiving a circle’s radius as a unit magnitude. Against the
    backdrop of the participants’ actions on these tasks, we characterize
    shifts in the participants’ unit circle meanings and we briefly
    describe how these shifts influenced their ability to use the unit
    circle in trigonometric situations.
rv: