
The tests devised by Piaget and his coworkers are quite simple because they only require a straight forward answer from the child, to questions such as 'Which one weighs more?' or 'What belongs here?'. This is only the beginning of the test, however, and can easily lead to an openended series of questions related to or a variation of the original question and how the answer was reached. From this, we can begin to see where the child is coming from and how their logic works. There are both strengths and weaknesses in Piaget's methods, though. They do reveal a lot about the child's thought processes, but the questioning is is quite unstructured. This leads to the fact that even a slight variation in questioning would probably offer a variation in the information obtained, and therefore the conclusions drawn may be incorrect. The tests Piaget devised cover a variety of areas of development:
Logical OperationsVisual Group objects
according to common attributes. The majority
can classify a group of objects in three different
ways from the age of 9. Tactilekinaesthetic Group objects
according to common attributes, but by touch
alone. Young children
find it harder to classify by tactilekinaesthetic
than by visual, but no great difficulties by age of
8. Anticipatory Classify
objects, but say what they will do instead
of physically doing it. All children
found it easier to classify than to
anticipate. Composition of
classes Understanding
of the relation between a set of
objects. Ability present
in most children by the age of 9. Class inclusion
or logical inclusion Understanding
of relationships between a group of objects and its
subgroupings. Hard to state
results  answers likely to be related to the
verbal sophistication of the child due to wording
of questions. Multiplicative
classification Classify using
two attributes at a time, such as size and
colour. Most able to
cope with multiplicative classification by the age
of 8. Multiplication
of classes (matrices) Consider two
attributes of an object and replace a missing
object in a matrix. The majority
have this ability by age 8. Multiplication
of relations Two relative
attributes have to be combined to give the next in
a series (i.e. each object is smaller and darker
than the previous one). The majority
have this ability by the age of 8.
Tests of ConservationConservation of
continuous quantity  liquids Appreciate that
variations in the shape of a container,do not
affect the quantity of liquid. Summary of
results unclear. Conservation of
continuous quantity  solids Appreciate that
changes in the shape of a solid (e.g. plasticine)
does not change the quantity of that
shape. A child who is
uncertain of his/her judgements (common in young
children) is more likely to be affected by
variables in the experiment, therefore there are
inconsistencies in the results. Conservation of
weight Appreciate that
changes in the shape of an object do not cause
changes in its weight. Results similar
to conservation of solids. Conservation of
volume Appreciate that
changes in the shape of an object do not change its
volume. Results similar
to conservation of solids and weight, but greater
inconsistencies. Conservation of
number Appreciate that
the number of objects in a collection remains the
same regardless of whether the collection is spread
out or bunched together. Young children
have difficulties in conservation of number, but
this can depend on whether they have begun school
or not. Conservation of
length Appreciate that
the comparative length of two objects (e.g. rods)
is unaffected by their relative positions or
straightness. Children find
it easier to conserve length than to conserve
continuous quantity, weight, volume or
number. Tests of Transitivity and SeriationTransitivity of
discontinuous quantity Ability to
appreciate the transitive relationship between
three collections of different numbers of
objects. Overall summary
below Transitivity of
weight Ability to
relate the weights of two objects, given the
relationship between their weights and a third
object. Overall summary
below Transitivity of
length Understanding
of the relationships between the lengths of three
rods. Overall summary
below Seriation Ability to put
a number of objects in order according to their
size, weight or numerousness. Overall
summary: remarkable consistency between tests. At
the age of about 8, most children have mastered the
concepts of transitivity and seriation.
Tests of Number ConceptsCorrespondence
and composition Ability to
relate each object in one collection to an object
in another collection (onetoone
correspondence). Overall summary
below Addition and
subtraction of one unit Recognise that
adding an object to a collection and than taking
one away leaves it the same. Overall
summary: a large number of children don't
understand what we consider very simple operations.
About 1/5 of seven year olds don't understand
addition and subtraction of one unit.
Tests of Spatial ConceptsSpatial
concepts Understanding
of simple geometrical ideas, such as the concepts
of vertical and horizontal. Even the 11
year olds who were tested did not fully understand
and realize the invariance of the vertical and the
horizontal. 