Most physics teachers would agree that one of the main reasons for her/his students to take physics is to learn to think critically. However, for years we have been assessing our students mostly on the knowledge of physics content (conceptually and quantitatively). Only recently have science educators started moving systematically towards achieving and assessing this critical thinking goal. In this paper we seek to show how guiding students to devise and test multiple explanations of observed phenomena can be used to improve their critical thinking.

1.
NGSS Lead States
,
Next Generation Science Standards: For States, By States
(
National Academies Press
,
Washington, DC
,
2013
).
3.
A.
Einstein
and
L.
Infeld
,
The Evolution of Physics
(
Simon and Schuster
,
New York
,
1966
).
4.
Eugenia
Etkina
, “
Millikan award lecture: Students of physics—Listeners, observers, or collaborative participants in physics scientific practices?
Am. J. Phys.
83
(
8
),
669
679
(
July
2015
).
5.
Eugenia
Etkina
and
Gorazd
Planinšič
, “
Light-emitting diodes: Exploration of underlying physics
,”
Phys. Teach.
52
(
4
),
212
218
(
April
2014
).
6.
Maja
Poklinek-Cancula
,
Gorazd
Planinšič
, and
Eugenia
Etkina
, “
Analyzing patterns in experts' approaches to solving experimental problems
,”
Am. J. Phys.
84
(
4
),
366
374
(
April
2015
).
7.
A similar experiment is described and explained in
Pirooz
Mohazzabi
and
Mark C.
James
, “
A simple apparatus for demonstrating fluid forces and Newton's third law
,”
Phys. Teach.
50
,
537
539
(
Dec.
2012
).
8.
The experiment is described in
Zhu
E-Qing
, “
A demonstration to show the upthrust exerted by air
,”
Phys. Teach.
26
(
6
),
401
(
Sept.
1988
).
9.
E.
Etkina
,
M.
Gentile
, and
A.
Van Heuvelen
,
College Physics
(
Pearson
,
San Francisco
,
2014
);
E.
Etkina
,
M.
Gentile
, and
A.
Van Heuvelen
,
The Physics Active Learning Guide
, 2nd ed. (
Pearson
,
San Francisco
,
2014
).
10.
E.
Etkina
,
D.
Brookes
, and
A.
Van Heuvelen
, “
Learning physics while practicing science: Introduction to ISLE
”,
a workshop that has been offered for the last 14 years at AAPT Summer meetings
.
11.
See, for example,
Eugenia
Etkina
,
Gorazd
Planinšič
, and
Michael
Vollmer
, “
A simple optics experiment to engage students in scientific inquiry
,”
Am. J. Phys.
81
(
11
),
815
822
(
Nov.
2013
);
Gorazd
Planinšič
and
Eugenia
Etkina
, “
Bubbles that change the speed of sound
,”
Phys. Teach.
50
(
8
),
458
462
(
Nov.
2012
).
12.
See, for example,
Gorazd
Planinšič
, “
Color mixer for every student
,”
Phys. Teach.
42
(
3
),
138
142
(
March
2004
);
Gorazd
Planinšič
, “
Water-drop projector
,”
Phys. Teach.
39
(
2
),
76
79
(
Feb.
2001
).
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