Code
Name 
Pretest 
Comments on pretest 
Posttest 
Comments on posttest 
lapim 

Right triangle & rectangle area compared.
No discussion of definition of area. 

Area explained with grids
(pictured) and linked to rectangle area formula. All cases of triangles
considered and triangle area formula fully justified. 
ihlew 

Right triangle & rectangle area compared.
No discussion of definition of area. 

Area explained with grids (pictured) and
linked to rectangle area formula. Area formula for right triangles
considered. Diagrams show extensions to general triangles. Brief reference
to parallelograms. 
horse 

Base and height discussed. Right triangle & rectangle
area compared. No discussion of definition of area. 

Area explained with grids (pictured).
Base and height discussed. Brief reference to parallelograms. 
dipit 

Right triangle & rectangle area compared. No
discussion of definition of area. 

Area explained with grids
(not pictured) and
linked to rectangle area formula. Base and height considered carefully.
Parallelograms
defined and related to triangles and to rectangles via dissections.
(But dissections not demonstrated.) 
kevoc 

Area considered briefly. Base and height considered.
Right triangle & square area
compared. 

Area explained with grids (pictured).
Triangles related to parallelograms. Area formula for parallelograms
explained in simple case. 
kitty 

Area explained in terms of grids. Triangle area formula "is faster,"
but author does not explain why it's true. 

Area explained with grids (pictured) and
linked to rectangle area formula. Area formula for right triangles
considered. Extensions to general triangles explained and diagrammed. Connections to
parallelograms mentioned. 
bytep 

Right (isoceles) triangles
and squares related. Mentions need to understand area, but no
discussion of definition of area. 

Area explained with
grids (not pictured).
Jump to parallelogram area. Areas of triangles and parallelograms linked.
Jump to formula. Areas of rectangles and parallelograms linked
by Euclid 35. Euclid 35 diagrammed. 
acegi 

Rectangle area formula.Rght
triangles related to rectangles,
giving triangle formula (for right triangles). Mentions need to understand
area, but no discussion of definition of area. 

Area explained with grids
(pictured) and linked to rectangle area formula. Area
formula for right triangles derived. Formulae for arbitrary triangles derived
with graphical and algebraic descriptions/support. 
lbugy 

Symbols A, b and h defined. Area
explained with grids (pictured), and linked to rectangle area
formula. Rectangles related to right triangles, giving triangle
formula (for right triangles). 

Area explained with grids
(pictured). Two congruent triangles assemble into a parallelogram.
Parallelogram defined. Base and height of a parallelogram. Euclid 35 stated.
Jump to area formula for parallelogram. Triangle area formula derived. 
zapdy 

Rectangles related to right triangles, giving triangle
formula (for right triangles). No
discussion of definition of area. 

Area explained with grids
(pictured) and linked to parallelogram area formula. Parallelograms
related to triangles via dissections. More on parallelogram area and area
formula. 
zoink 

Base and height discussed. Right triangle & rectangle
area compared. No
discussion of definition of area. 

Area explained with grids (pictured) and carefully
linked to rectangle area formula. A parallelogram is a rectangle "shifted",
and has same area as rectangle. Any triangle can be combined with a copy
of itself to make a parallelogram, giving formula. Base and height 
basum 

Area "is a measurement
of the in side.." Base and height considered. Grids
illustrated. Dissection of rectangle. 

Area explained with grids (pictured) and linked
to rectangle area formula. Area formula for right triangles derived. Two
copies of a nonright triangles make a parallelogram. Base and height
of triangles. Euclid 35 stated and related to the context. 
alemo 

Area is like "floor of ...[a] room." Rectangle
area formula.Rght triangles related to rectangles, giving triangle formula
(for right triangles). 

"Area is the space
enclosed.." A, b,
and h explained carefully and illustrated. Parallelogram area formula
gives triangle area by cutting
on diagonal. Area
explained with grids (pictured) and linked to rectangle area formula. Area
formula for right triangles derived. Parallelograms dissect and reassembled
to rectangles (wide base case illustrated, and recognized as special). 
ennae 

Base and height diagrammed. Area is "amount of
space inside". Cutting a square on the diagonal explains the formula.ight
triangle & square
compared. 

Area explained with grids (pictured) and linked
to parallelogram area formula. Parallelograms related to triangles
via dissections. Euclid 35 diagrammed and used to show that for any parallelogram
there is a rectangle with same base, height and area. Proof of Euclid
35. 
zxvtr 

"The formula is true because a triangle is half a rectangle." 

Area explained with grids (not pictured) and linked
to rectangle area formula. Area
formula for right triangles derived. Possibility of generalization to other
triangles asserted. 
catil 

Formula for area of
square lead to triangle area formula by cutting square on diagonal. 

Area is like "amount of grass it would take ...
to cover [a] field." Rectangle area formula leads to triangle area formula
by diagonal cut. 
cepod 

Rectangles related to right triangles, giving triangle
formula (for right triangles). No discussion of definition of area. 

Area explained with grids (pictured) and
linked to square and rectangle area formulae. Rectangle area formula leads
to triangle area formula by diagonal cut. Euclid 35 quoted. for any parallelogram
there is a rectangle with same base, height and area. 
mbrir 

Area is "space enclosed." Base and height explained and pictured. 

Rectangle and parallelogram
area formulae mentioned. Parallelograms related to triangles via dissections,
explaining triangle
area formula. 
moron 

Area is "space inside." Base of a triangle
is "longest side." A square is made of 2 triangles. Other comments. 

Area is "space enclosed." Any
side of a triangle may be base. Triangles relate to parallelograms. Diagram
from Euclid 35. 
smile 

Area explained with grids (pictured) and very carefully
linked to rectangle area formula. A triangle is 1/2 of a rectangle (by folding). 

Triangle area formula comes from parallelograms. Area is amount of space
inside. Graph paper. Every triangle is half of a parallelogram. Parallelograms
dissect to rectangles by various means. 
cojoc 

Area explained with grids (pictured) and carefully
linked to square area formula. A triangle is 1/2 of a square. Every triangle
is half a "quadrilateral." 

Area explained with grids (pictured) and carefully
linked to square area formula. A triangle is 1/2 of a square. Every triangle
is half a "quadrilateral." 