id: 06455418
dt: j
an: 2015e.00959
au: Trocki, Aaron
ti: Evaluating and writing dynamic geometry tasks.
so: Math. Teach. (Reston) 107, No. 9, 701-705 (2014).
py: 2014
pu: National Council of Teachers of Mathematics (NCTM), Reston, VA
la: EN
cc: U70 G40 D39
ut: geometry; use of technology; dynamic geometry software; activities; task
analysis; mathematical tasks; professional development
ci: ME 2004a.00552
li: http://www.nctm.org/publications/article.aspx?id=42075
ab: Summary: The advent of dynamic geometry software has changed the way
students draw, construct, and measure by using virtual tools instead of
or along with physical tools. Use of technology in general and of
dynamic geometry in particular has gained traction in mathematics
education, as evidenced in the Common Core State Standards for
Mathematics. Research has shown the potential benefit of using
technology, particularly dynamic geometry tasks, to promote
mathematical reasoning. The Common Core State Standards for Mathematics
(CCSSM) high school geometry standards require students to “make
formal geometric constructions with a variety of tools and methods”,
and dynamic geometry software is among the tools listed. Further, {\it
K. F. Hollebrands} [J. Math. Behav. 22, No. 1, 55‒72 (2003; ME
2004a.00552)] has noted that within such dynamic environments students
have opportunities to consider invariant relationships through dragging
as well as make corresponding conjectures and conclusions. However,
little guidance is provided to teachers for evaluating the quality of
dynamic geometry tasks, much less for writing their own. The purpose of
this article is to introduce a framework for analyzing and writing
dynamic geometry tasks that are designed to engage students in
mathematical reasoning. The author begins by asking readers to compare
two sample tasks, each of which is designed to engage students in
developing and testing conjectures about parallelograms. He then
introduces the framework and illustrates how it can be used to evaluate
the potential of each task in accomplishing the desired result. (ERIC)
rv: