Basic HTML Version
Q
uantitative
R
easoning &
P
roblem
S
olving
196
© 2014 Pacific Crest
A
re You Ready?
Before continuing, you should be able to ...
I can...
OR
Here’s my question...
name five techniques for validating my
learning
apply three different scales for measuring
the quality of my learning
name five techniques for validating my
work
P
lan
How to complete the activity
1. Inventory the set of validation techniques classified by learning and by problem solving from your
discovery activity.
2. Expand this list based upon the reading that you did.
3. Answer the Critical Thinking Questions.
4. Be prepared to share three significant differences between validating learning and validating the
strength of a problem solution.
5. Complete the remainder of this activity (from Demonstrate Your Understanding through Assessing
Your Performance) on your own, or as directed by your instructor.
M
odel(s)
Exemplars and representations
M
odel
1: C
ommon
S
ense
C
heck
The solution to a problem should make sense within the context of the problem. For example, if you
are to determine the speed a car will be traveling in some situation, it does not make sense to arrive
at a solution that indicates that the car would be traveling at 500 mph. Some mistake has occurred.
It may be simply a computational error or it may be a more difficult-to-discover conceptual error.
M
odel
2: W
orking
B
ackwards
To validate if the factored form of
2
12 23 5
x
x +
−
is (6 1)(2 5)
x
x
− −
, we can work backwards by
multiplying the two factors together.
2
2
(6 1)(2 5) 6 (2 ) 6 ( 5) ( 1 2 ) ( 1)( 5) 12 30 2 5 12 32 5
x
x
x x x
x
x
x x
x
x
− − =
+ − + −
+ − − = − − + = − +
The correct result would be
2
12 23 5 (3 5)(4 1)
x
x
x
x
− + = − −
which you can validate by working
backwards.