UNDERSTANDING DIAGRAMS AND PICTURES IN SCIENCE
1. Compare and Contrast Diagrams
A “compare and contrast diagram” is used when two different organisms, events, or
processes are being shown so that students can find the similarities or differences in the
organisms, events, or processes. For higher order questions, the similarities or differences are
used to derive information regarding the similarities or differences. A graphic organizer may be
used to help students visualize.
2. Before and After Diagrams
Before and after diagrams are used when the same organism, event or process is being
shown at two different time periods – generally the beginning and the end. Before and after
diagrams are similar to compare and contrast diagrams, but students will generally be looking
for the differences in the “after diagram” as compared to the “before diagram.” In most cases,
student will be expected to explain the reason for change in the organism, event or process.
3. Representational Diagrams
 2004 Bart Bookman NYS Biology-Chemistry Mentor Network, Finger Lakes Community
College, Canandaigua NY 14424. Copyright allows not-for-profit organizations to duplicate
materials for teacher and student use.
Representational diagrams are used to make “complex or real organisms, organs,
systems events, and processes” into simpler, easier-to-read and understand diagrams. The
best representational diagrams use structurres that are not only simple, but also allow the
students to understand the basic structure, which can give a strong indication of the function.
They also allow three-dimensional structures to be drawn in two-dimensions, such as outer
shape with its inner strucutres, cross section, longitudinal section, etc. Objects, organisms, or
process devices that are too difficult to accurately draw are reduced to diagrams that are “good
enough” to demonstrate the specific information. Obviously, representational diagrams are
most effective when first introducing a structure, organism, or process. Very often,
representational diagrams are used later as “symbols” for more complex diagrams and written
information.
4. Parts Diagram
Parts diagrams generally show a strucutre and its major parts. Usually, the student is
asked to identify a part by its name, from its function, its location, or its general shape.
Numbers or arrows are used to point out a label or a specific part. When students look at a
parts diagram, they must be clear which view (front, back, top, bottom or side) they are
observing the structure from. In many cases, it is also important for them to understand if it is
an overall view or a section.
 2004 Bart Bookman NYS Biology-Chemistry Mentor Network, Finger Lakes Community
College, Canandaigua NY 14424. Copyright allows not-for-profit organizations to duplicate
materials for teacher and student use.
5. Step-by-Step Diagrams
Step-by-step diagrams are used to demonstrate a sequence in a process, event, or
phenomenon. They can be thought of as either multi-compare and contrast diagrams or multibefore and after diagrams at different time periods. The major questions for these type of
diagrams are related to “What happens between the different steps or stages?”, “How do the
changes occur at each step or stage?”, or “Why do the changes need to occur at each step or
stage”?
6. Flow Chart/Concept Map Diagrams
Flow chart diagrams put main words or phrases in circles or boxes and then use arrows
to indicate the sequence of events or how they are related. Concept maps are a variation in
which words or phrases are written alongside or through the arrows to indicate what specific
action occurs to get to the next cirle or box. If two or more arrows are drawn from a circle or
box, it means that the sequence of events is continuing in two or more directions at the same
time. Flow charts are used to combine step-by-step diagrams when there is more than one
possible pathway, or if more than one pathway can be followed at the same time. Flow charts
diagram complex events or phenomenaand are easy to read visusal organizers.
 2004 Bart Bookman NYS Biology-Chemistry Mentor Network, Finger Lakes Community
College, Canandaigua NY 14424. Copyright allows not-for-profit organizations to duplicate
materials for teacher and student use.
7. Complete Process or 1-Picture Story Diagrams
Compete process diagrams are seen as “one picture stories.” An entire process, event
or phenomenon is shown in one picture. These diagrams differ from step-by-step diagrams in
that they involve more than one specific process. Usually arrows indicate the sequence of
events - as there may be not be a typical layout of the process. Compete process diagrams
can utilize representation diagrams, before and after diagrams, and parts diagrams to represent
the complete process or story.
Using Diagrams in Teaching and Assessment
Below are a variety of activities that can be used in the classroom or on an assessment. You
can use as few or as many as you need.
1. Compare and Contrast Diagrams
 List similarities and differences
 Make a “t-chart” of observations
 Make a “comparison table”
 Identify the objects/processes indicated by the arrows or letters
 Compare and contrast the objects or processes indicated by the arrows or letters
 “See the similarity” in objects we believe to be quite different
2. Before and After Diagrams
 2004 Bart Bookman NYS Biology-Chemistry Mentor Network, Finger Lakes Community
College, Canandaigua NY 14424. Copyright allows not-for-profit organizations to duplicate
materials for teacher and student use.
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Discuss or list the difference(s)
Explain the reasons for the change(s)
Identify the process(es) involved in the before and after change
Make a “comparison table”
List factors that might influence the differences between the diagrams
Determine how the outcome might be changed
Draw an intermediate picture between the before and after diagrams
Describe how the after diagram could be changed back into the before diagram
Describe the set up or experimental design
Label diagrams that are unlabelled
3. Representation Diagrams
 Describe how the diagram represents the “real thing”
 Compare and contrast two or more representational diagrams for the same thing
 Compare and contrast the representation diagram to reality (or a picture of it)
 Describe how the diagram allows you to understand the basic structure/function
 Describe how three-dimensional structures are drawn in two-dimensions
 Draw a diagram from a different view or section
 Label a representational diagram
 Identify all the processes involved in the diagram
 Draw a representational diagram from a description
 Make a “key” for symbols used in a representational diagram
4. Parts Diagrams
 Identify parts by their location and general shape
 Identify parts from descriptions of their functions
 Describe the structure/function of a specific part
 Explain how individual parts function in the entire organism/object
 Explain how structure of a part is related to its function
 Describe how parts may differ in other organisms/objects
 Explain how parts have changed over time
 Compare and contrast a part to other similar parts
 Label a parts diagram
 Compare and contrast two parts diagrams
5. Step-by-Step Diagrams
 Write a procedure
 Write a description of each step
 Compare and contrast steps
 Describe/explain how changes occur at each step
 Describe/explain why changes need to occur at each step
 Organize out of order steps
 Defend a sequence of steps
 Identify missing or incomplete information from a specific step
 Identify variables that could change between steps or interfere with a specific step
 Identify variables that could be counted or measured to express differences in steps
 Expand or condense into a storyboard
 2004 Bart Bookman NYS Biology-Chemistry Mentor Network, Finger Lakes Community
College, Canandaigua NY 14424. Copyright allows not-for-profit organizations to duplicate
materials for teacher and student use.
6. Flow Chart/Concept Map Diagrams
 Write a description of the process phenomenon from the flow chart/concept map
 Create a different flow for the same information
 Convert to a series of step-by-step diagrams
 Modify the flow chart/concept map to reflect new information
 Introduce a new variable
 Draw a flow chart/concept map from a reading or written description
 Fill in an incomplete flow chart/concept map
7. Complete Process or “1-Picture Story” Diagrams
 Write out the entire process or phenomenon
 Identify and describe the process(es) in the diagram
 Create a multi-frame storyboard
 Make into a flow chart/concept map
 Compare and contrast processes in the diagram
 Modify the diagram to include new information
 List processes involved in the diagram
 Identify all parts involved in the process
 Make predictions from the diagram
 Evaluate the diagram for “understandability”
 2004 Bart Bookman NYS Biology-Chemistry Mentor Network, Finger Lakes Community
College, Canandaigua NY 14424. Copyright allows not-for-profit organizations to duplicate
materials for teacher and student use.