External Representations in the Teaching and Learning of Introductory Chemistry

doi:10.4236/ce.2011.25067

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Creative Education

2011. Vol.2, No.5, 461-465

External Representations in the Teaching and Learning of

Introductory Chemistry

James R. Cox, Bethany W. Jones

Department of Chemistry, Murray State University, Murray, USA.

Email: [email protected]

Received October 3rd, 2011; revised November 15th, 2011; accepted November 22nd, 2011.

This manuscript describes the role that external representations, such as diagrams and sketches, can play in or-

ganizing and learning concepts presented in a one-semester chemistry course (general, organic and biochemistry)

designed for nursing students. Although external representations are typically found in chemistry textbooks and

instructor-drawn notes, students are usually not taught or prompted to use various types of external representa-

tions to promote learning. Representations created by an instructor and a student are discussed to highlight ef-

fective ways to foster student participation in creating various diagrams. In addition, a student provides a per-

spective on the educational value of creating external representations and the roles of visual thinking and crea-

tivity in learning introductory chemistry. Although the model for this approach has been an introductory chemis-

try course, this approach can be widely applied across disciplines.

Keywords: Visual Thinking, External Diagrams, Active Learning

Introduction

The availability and diversity of instructional methods in sci-

ence classrooms has increased tremendously in last decade. As

a result, the lecture format has been redesigned and more active

forms of teaching and learning have been developed (Derting &

Cox, 2008; Derting & Ebert-May, 2010; Deslauriers, Schelew,

& Wieman, 2011; Haak, HilleRisLambers, Pitre, & Freeman,

2011; Lee & Jabot, 2011; Mazur, 2009). This comes at a time

when the amount of content and information available in scien-

tific disc iplines is e ver expanding. At the same time, some ha ve

heralded the end of the information age and insist we are in an

interaction age (Milne, 2007) where student success depends on

meaningful interactions with instructors, each other and infor-

mation. Daniel Pink has suggested we have left the information

age and entered a conceptual age where right-brain aptitudes

such as creativity, design and pattern recognition will be indis-

pensible (Pink, 2005).

Another important issue in the current educational environ-

ment is the extent metacognitive and learning skills should be

incorporated into science courses, especially at the introductory

level. Metacognition is a complex area related to the manage-

ment of one’s own learning and is known to be an important

domain in student learning and success in chemistry (Cooper &

Sandi-Urena, 2009; Rickey & Stacy, 2000; Tsai, 2001). In ad-

dition, a recent report made a strong argument for teaching

introductory science students less content and more learning

skills in an effort to provide a richer learning experience and

promote science literacy (Coil, Wenderoth, Cunningham, &

Dirks, 2010).

Although robust and lively debates about content, course de-

sign and learning skills are important, the fact remains that

there are numerous students struggling to succeed in introduc-

tory science courses. In many ways, the solution to this prob-

lem boils down to what a recent report termed the Carnegie

Hall hypothesis, which relates intensive “practice” to the suc-

cess of underprepared students (Haak et al., 2011). The authors

of this recent report note that effective forms of practice require

students to challenge previous conceptions and explain their

thinking. For some students, practice only comes in the form of

working additional problems at the end of textbook chapters.

Although working problems is imperative, students can benefit

from having a wider array of options to practice concept mas-

tery and problem-solving strategies. One option is to introduce

students to the concept of visual thinking and the role that visu-

alization can play in tackling misconceptions and describing

thought processes (Gilbert, 2005; Mathewson, 1999; Schönborn

& Anderson, 2006; Stranger-Hall, Shockley, & Wilson, 2011).

The opportunity to use creativity and right-brain skills to tackle

more analytical and quantitative tasks may help a broad range

of students, even if some content has to be sacrificed.

External Representations

This manuscript describes how a chemistry instructor pro-

mpted students in his introductory chemistry course to create

diagrams and sketches (external representations) to solve prob-

lems and learn concepts and how one particular student in the

course responded. External representations can be defined as

visual and spatial displays used to promote, discovery, memory,

inference and calculation and will be used as a broad term to

describe sketches, diagrams or illustrations generated by hand

or on a computer (Schönborn & Anderson, 2006; Suwa &

Tversky, 2002; Tversky, 2002). The literature describes the

educational and psychological value of external representations

in terms of memory, expressing ideas, making connections,

pattern construction and recognition and problem solving

(Gilbert, 2005; Gobert & Clement, 1999; Hall, Bailey, & Tillman,

1997; Larkin & Simon, 1987; Mathewson, 1999; Mayer &

Gallini, 1990; Ramadas, 2009). One of the most powerful as-

pects of creating external representations can be realized when

students see new ideas and concepts emerge after drawing a

sketch or diagram. These unintended discoveries provide a

greater context to the material and a scaffold in which to de-

velop new ideas or a greater understanding of a body of infor-

mation (Tversky, 2002).

J. R. COX ET AL.

462

Deliberate Practice

There is also an expanding body of evidence that points to

the educational value of learner-centered pedagogies that have

students actively engaged in learning activities and deliberate

practice strategies (Derting & Ebert-May, 2010; Deslauriers et

al., 2011; Haak et al., 2011; Stranger-Hall et al., 2011; Weimer,

2002). Although this manuscript describes the use of external

representations in an introductory chemistry course, the meth-

ods discussed are just one way to promote deliberate and pro-

ductive practice sessions. As a result, the aim of this work was

not to assess the impact on student learning; rather it was to

develop a strategy to get students to construct external repre-

sentations and to obtain detailed information from a student that

found value in this approach. The next two sections are written

by an instructor (JRC) and a student (BWJ) in an introductory

chemistry course (general, organic and biochemistry) designed

for nursing students. Although the representations described in

the manuscript are for a chemistry course, the use of visual

thinking and student-generated diagrams should be of interest

to educators across disciplines. It should be noted that the type

and nature of the external representations described in this

manuscript are not typically found in traditional chemistry

textbooks. The goal of this approach was to show students how

to use their own creativity to generate representations that inte-

grate information and prompt them to see the interconnected-

ness of topics and ideas.

Role of Instructor (JRC)

As the instructor, I played two roles in introducing external

representations into this introductory chemistry course. The

first involves my use of sketches or diagrams during lecture and

discussion to provide new ways to present, analyze and inte-

grate information and concepts. An example of this type of

representation is shown in Figure 1 and is related to the strategy

used to perform unit conversions. This diagram, coupled with a

few practice problems, was used to introduce the mechanics of

solving these types of problems and the steps common to most

conversions (one unit is converted to another unit, usually with

one or more intermediate steps using conversion factors). Fig-

ure 2 shows another representation concerning the naming and

properties of carboxylic acids. A textbook typically presents the

rules of carboxylic acid nomenclature in text form and physical

property information (such as boiling point and water solubility)

in tabular form. The diagram in Figure 2 was constructed to

integrate these important areas and supplement the textbook

and course notes on nomenclature and properties. The purpose

of this diagram was to present some essential information on

carboxylic acids in a more visual form, although some text is

used to make key points.

It is likely that students will draw more educational value

from constructing their own diagrams compared to just using

ones supplied by an instructor (Gobert & Clement, 1999; Hall

et al., 1997; Stranger-Hall et al., 2011). Therefore, the second

role I played was mentoring students how to create their own

diagrams. Constructing useful diagrams is not easy for most

students and incorporating them in lecture or class discussions

may not be enough to prompt students to make their own. Class

time can be used for students to practice making various exter-

nal representations. One approach was to have a class art show

where student groups were tasked with making diagrams that

illustrate how to solve a particular problem, analyze concepts or

Figure 1.

An instructor-generated diagram related to unit

conversations.

Figure 2.

An instructor-generated diagram that integrates various topics related

to carboxylic acids.

dissect molecules (Figure 3). Another approach I used was to

work one-on-one with students during office visits. These are

typically the students that need help and can benefit most from

a fresh approach to solving problems, organizing information

and learning concepts through representations.

Student External Representations (BWJ)

In courses outside the science s, I was alway s able to combine

my creativity and right-brain aptitudes with more traditional

methods (rewriting notes, listening to audio recordings of lec-

tures, etc.) to maximize my learning. However, when I started

in the Introductory Chemistry course, I was not sure how to use

my creative skills to further my learning. I took copious lecture

notes, read the textbook and worked the problems at the end of

the chapters; however, it was difficult to see how various parts

of the chapters fit together and the material seemed complex,

foreign and intimidating. This changed when the instructor

introduced the concept of creating diagrams to aid in integrat-

ing material and solving problems. This allowed me to tap into

my natural disposition of working though problems creatively

and visually and I was able to process and retain course infor-

mation much more readily and effectively. As a result, I now

think more visually when learning science and solving prob-

lems and utilize more creative learning methods in courses

within my nursing program.

The external representation in Figure 4 was created in order

to visualize and help retain the process of two fundamental

tasks in chemistry: 1) define and calculate the molecular weight

of a molecule from the periodic table and 2) calculate the mass

(in grams) of a molecule (from moles) using a conversion factor.

This external representation also helped me maintain the correct

J. R. COX ET AL. 463

Figure 3.

A student-generated poster used in a chemistry art show. Posters of this

type were generated by student groups to highlight important aspects of

chemistry and to demonstrate the different types of diagrams that can

be created by students and student groups.

Figure 4.

A student-generated diagram related to molecular weight and mole-to-

mass conversions.

units (amu, grams, and moles) throughout the problem by using

color coding. When working problems related to molecular

weight and the conversion of moles to grams, I was able to

refer back to this picture in my mind, linking the periodic table,

molecular weight, and the conversion factor, like a map.

The external representation in Figure 5 was created in order

to visualize and retain the Gas Laws by providing the following:

1) a clear, visual picture of how the laws of Gay-Lussac, Boyle,

and Charles, are integrated to form the Combined Gas Law and

2) an understanding of how the Combined Gas Law, Avo-

gadro’s Law and the gas constant combine to form the Ideal

Gas Law. Prior to drawing this external representation, I did not

fully appreciate the interconnectedness of the gas laws. They

initially appeared to me as separate laws I would be required to

memorize from the textbook. It was not until creating this ex-

ternal representation that I was able to fully understand how

each law contributes to the overall behavior of gases under

certain conditions.

External representations can also be used to analyze ques-

tions and problems missed on quizzes or examinations. Many

students do not spend enough time investigating the reasons

why they missed a particular problem. As a result, they do not

take advantage of excellent opportunities to identify weak-

Figure 5.

A student-generated diagram that shows the relationship

between the various gas laws.

nesses in logic, content knowledge and problem-solving strate-

gies. Creating diagrams can be an effective way to reexamine

material and use assessments as a tool to promote learning and

not just for measuring learning.

Figure 6 shows a diagram created to analyze a problem

missed on an examination. I made this representation with text

and structures in order to construct a problem-solving process

that allowed me to reverse any inaccuracies or oversights by

crafting a detailed pathway to victory (correct answer) through

visualization. This simultaneously created a visual memory

with the capability to maintain a lasting impression of the fac-

tors associated with water solubility. The visual and integrative

nature of Figure 6 does not make the question any less complex,

just more discernable and accessible. Therefore, constructing

these types of diagrams allows me to learn from my mistakes

and provides a process to better analyze future questions. Ulti-

mately, it is less about getting questions correct on examina-

tions and more about learning the concepts associated with my

courses and developing habits of the mind that allow me to

think criticall y a n d cre atively.

Conclusion

Students are often presented information, concepts and prob-

lems in various forms, but are rarely taught how to organize and

integrate material in a way that supports learning (deliberate

practice). Students must be able to construct a conceptual

framework of ideas and facts and organize information in way

that it can be easily recalled and applied (NRC, 2000). This

manuscript has addressed many types of external representa-

tions and demonstrated how they can be used to organize and

integrate information. Also, the roles that instructors and stu-

dents can play in generating representations have been de-

scribed. Overall, the process of incorporating external repre-

sentations into a course can be summarized as Initiation-Op-

portunity-Visibility. Typi cally, students have to be prompted to

draw diagrams and instructors can initiate the proc ess by using

external representations during class and helping students make

their own diagrams. This can provide an opportunity for stu-

dents to use right-brain aptitudes to help them learn material

such as introductory chemistry. Also, it provides an opportunity

for some students to be introduced to design and symphony,

two of the senses described by Pink as important in the con-

ceptual age (Pink, 2005). Often, students who do not succeed in

courses such as introductory chemistry fail to grasp or visualize

J. R. COX ET AL.

464

Figure 6.

A student-generated diagram used to analyze a question missed on an

examination.

the interconnectedness of complex ideas and problem variables.

External representations and visual thinking have the potential

to make complex ideas and problems more accessible and visi-

ble to a broad range of students who struggle in the areas of

information organization and synthesis, pattern recognition or

the ability to identify or focus on the hierarchical nature of

systems.

These concepts are related Dan Roam’s approach to solving

business problems and selling ideas with pictures (Roam, 2008).

Roam suggests that the real value of visual thinking is to make

complex issues understandable by making them visible, not

simpler. This has direct and significant consequences in teach-

ing at all levels. Instructors have to teach students to appreciate

and analyze the complexities of science, even in introductory

courses. Although simplification has its place in teaching and

learning, the principles of scientific disciplines can only be

broken down so far and the beauty and essence of many sys-

tems lies in their complexity.

Acknowledgements

We thank the Department of Chemistry and the College of

Science, Engineering and Technology at Murray State Univer-

sity for support of this project. The authors also acknowledge a

Hewlett-Packard Technology for Teaching Grant and a Micro-

soft Tablet PC Technology, Curriculum, and Higher Education

Grant for support of tablet-related instructional activities.

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