Venn diagrams
Chris
Joyce (2008)
A
Venn diagram is a type of graphic organiser. Graphic
organisers are a way of organising complex relationships
visually. They allow abstract ideas to be more visible.
Although Venn diagrams are primarily
a thinking tool, they can also be used for assessment.
However, students must already be familiar with them
before they can be used in this way.
When
to use
Venn diagrams are used to compare
and contrast groups of things.
They are a useful tool for formative
assessment because they:
In science, they are helpful for
classification.
As an accepted convention for representing
similarities and differences, knowing how to use them
contributes to the Key Competency, Using language,
symbols, and texts.
The
theory
Venn diagrams originate from a branch
of mathematics called set theory. John Venn developed
them in 1891 to show relationships between sets. They
are now used across many other disciplines.
Information is usually presented
to students in linear text. Especially when there is
a lot of information, it is difficult to see relationships
in this format. Venn diagrams enable students to organise
information visually so they are able to see the relationships
between two or three sets of items. They can then identify
similarities and differences.
How
the strategy works
A Venn diagram consists of overlapping
circles. Each circle contains all the elements of a
set. Where the circles overlap shows the elements that
the set have in common. Generally there are two or three
circles. Any more and the exercise becomes very complicated.
The following science example compares
the features of bats and birds.
The following is a maths example:
What
to do
Creating a Venn diagram
If the assessment focus is on organising
information:

Students view written text, pictures,
diagrams, or video/film about two (or sometimes
three) items that have some related characteristics.

Identify what items they want
to compare (e.g., birds and bats).*

Draw two overlapping circles.
Label each circle (Bird, Bat).

In each circle, fill in the characteristics
of each item.

Identify which characteristics
appear in both circles. These characteristics go
in the intersection (where the two circles overlap).

Sometimes features that don't
fit in either set are included. E.g., in the maths
example, if all numbers between 1 and 30 were included,
some would not be a multiple of either 3 or 5. These
are placed outside the circles.
It is preferable that students then
use their Venn diagram to compare the sets.
*Sometimes the first step
is to draw a rectangle and identify the universal set.
For example, in the science example above, the universal
set might be Animals that fly. The circles for birds
and bats are then drawn inside the rectangle.
Reading a Venn diagram
If the assessment focus is to interpret
a Venn diagram:

Ask questions about the similarities
and differences that the Venn diagram illustrates.

Provide true/false statements,
e.g., 10 is a multiple of 3 and 5.

Ask questions about, or discuss
the two sets. For example, students may be able
to say that bats have some similarities to birds,
but are not birds because they don't lay eggs or
have feathers.

If appropriate, ask questions
that encourage students to make generalisations,
e.g., Can we classify a bat as a member of the bird
family?
Limitations
When trialling ARB resources we have
found that many students do not use Venn diagrams well.
Some are unfamiliar with them. If using Venn diagrams
as an assessment strategy, students must have already
demonstrated that they know how they work, to ensure
that the assessment is valid.
Adapting
the strategy

Venn diagrams are widely used as
a tool for thinking. They are therefore also a useful
teaching strategy.
 They
can be useful for practising making logic statements,
e.g., if/then, all/some/no, may be.
 When
teaching students about Venn diagrams, or working
with young students, use concrete materials, such
as postits, cards, string, or hoops, which students
can move around.

Computer programmes such as Inspiration
are useful for creating Venn diagrams.
Examples
of ARB resources that include Venn diagrams
Assessment strategies  ARB
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