It Can�t Be Done! Or Can It? by OhLy6424

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									  Assessing Critical Thinking
  in the Science Classroom



     Paula Lemons
The University of Georgia
  September 26, 2008
For this workshop
“assessment” is
    Any tool used to measure students’
     knowledge or skills
    Examples: exam questions, writing
     assignments, oral presentations, etc.
I hope you will . . .

     Connect with others who are
      interested in assessing critical
      thinking.
     Become familiar with one method for
      preparing critical-thinking
      assessments.
     Gain a process for critiquing your own
      assessments to determine if they are
      actual measures of critical thinking.
A Question to Consider

    What comes to mind when you think
     about “critical thinking in the science
     classroom?”
My courses lacked

    Any proof that my assessments
     were real measures of critical-
     thinking skills.
I needed

 1.   An explicit definition of critical
      thinking.
 2.   A systematic way to recognize
      and reward critical thinking.
A Take Home Point

    Assessing critical thinking
     involves
        specifying critical-thinking goals
        linking them to course grading
         plans
    This is not simple!
What method can we use?

    Define the critical-thinking skills
     we want students to develop.
    Design assignments that require
     these skills.
    Think, in advance, about grading
        i.e., How will we look for and reward
         not only content knowledge but also
         critical-thinking skill?
Bloom’s Taxonomy of Educational
Objectives*




     *From Bloom, B. S., ed. 1956. Taxonomy of Educational Objectives:
     The Classification of Educational Goals. McKay, New York.
Example: mRNA diffusion through a nuclear membrane.
In eukaryotes mRNAs must travel through the nuclear membrane (a double lipid-bilayer) to the
cytoplasm in order to be translated into proteins. Based on what you know about the chemical
structure of mRNA and of lipid bilayers, choose the picture below that you think more accurately
models the movement of mRNAs. Explain the rationale for your choice. (6 points)

                                                                                        mRNA
                                          mRNA
 Nuclear                                            Nuclear
membrane                                           membrane




                                              Cytoplasm
  Nucleus

                                                     Nucleus
                                                                                         Cytoplasm

            Choice 1. mRNAs diffuse through               Choice 2. mRNAs move through a
            the nuclear membrane.                         channel in the nuclear membrane
                                                          that is created by a protein.


           Choice: ______      Rationale:
Knowledge needed to answer question:
• Chemical structure of mRNA and lipid bilayers.

Critical thinking skills needed to answer the question:
• Application – Students must address mRNA movement in the cell using
knowledge of mRNA structure and lipid bilayers.
• Analysis – Students must examine both scenarios and decide which is more
likely to be the way that mRNA moves from nucleus to cytoplasm.

Complete answers will include each of the following:
I       Chemical structure of biomolecules:
        IA       mRNA – charged or polar molecule
        IB       lipid bilayer – hydrophobic interior (NOTE: mentioning the
                 hydrophilic head groups is not essential to this answer).
II      Point out that the lipid bilayer cannot accommodate a charged
        molecule via diffusion, thereby eliminating Choice 1.
III     Point out that since diffusion won’t work, an alternative
        mechanism is needed. Therefore, Choice 2 is correct (mRNAs move
        through a protein channel).
                      Grading rubric




Knowledge component                    Critical thinking
                                        components
Evaluating sample assignments
     What, if any, content knowledge is required?
     What, if any, critical-thinking skills are
      required? Define these skills as explicitly as
      possible.
     Is it possible to come up with a correct and
      complete answer if you have the content
      knowledge but not the critical-thinking skill?
     Is it possible to come up with a correct and
      complete answer if you lack the content
      knowledge but have the critical-thinking skill?
     What else do you observe about these
      questions?
What are the benefits of
systematically assessing CT?
 Provides data about
     The source of student errors (content vs.
      critical thinking)
      Misconceptions about concepts
Example: mRNA diffusion through a nuclear membrane.




              36% of students selected choice 2 – mRNA
               moves through channel – with either no
               rationale or an incorrect rationale.
              Follow-up question – similar but molecule was
               uncharged.
              43% of students said that the uncharged
               molecule would need a channel for transport.
              Question: What is driving this error in student
               answers? (1) Misconceptions about membrane
               transport? and/or (2) A mistake in the way
               material is presented?
What are the benefits of
systematically assessing CT?
 Provides data about
    The source of student errors (content vs. critical
     thinking).
    Misconceptions about concepts.

 Clarifies course expectations for students
    e.g., through review of valid critical-thinking
     questions and rubrics in class; discussion of
     specific CT expectations in class, in office hours,
     on syllabus
 Provides a framework for instructors to make
  decisions about content, assignments,
  readings, etc.
Special Thanks to . . .

 Dr. Ahrash Bissell, ccLearn
 Dr. Jeremy Hyman, Western Carolina
  University
 This work has been supported by
     Arts and Sciences Council on Faculty
      Research, Duke University.
     Trinity College of Arts and Sciences, Duke
      University.

								
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