AARE2002: Paper CHO02101
best accompanied by some note to clarify what is meant by each decision in the key (see figure
6).
1. Is the child obviously playing?
(a) Yes - go to 3
(b) No - go to 2
2. Is the child exploring or examining play objects or the play partner ’s play?
(a) Yes - Exploratory
(b) No - Non-play
3. Does the play consist only of play objects being used in a physical manner?
(a) Yes - go to 4
(b) No - go to 5
4. Are the play objects being organised spatially?
(a) Yes - Constructive Play
(b) No - Functional Play
5. Are rules obviously being followed?
(a) Yes - Game with Rules
(b) No - Pretend Play
Figure 4: Key for classification of cognitive level of play - list format
3 Conclusion
The use of a binary key for the classification of behaviour can improve the consistency of classi-
fication. Since the decisions required of the classifier are prioritised and simplified, less knowl-
edge of the classification scheme being used is required. Thus, improved consistency and inter-
observer agreement can be obtained, without the need for extensive training of observers.
In addition, the act of constructing a key guarantees that the categories into which the ob-
served behaviour is to be classified are mutually exclusive, complete (ie exhaustive), and can
be distinguished from each other by observation. These properties are required for any set of
categories to be considered correct. The key can also warn the researcher if any single category
contains multiple distinguishable behaviours. This strongly suggests that the construction of a
key is a valuable tool for the validation of a classification scheme, even if there is no intent to
use the key for actual classification work.
Lastly, we warn against regarding the binary key as a panacaea for classification difficul-
ties. Ambiguous behaviour is still ambiguous behaviour, and while the key prioritises and
simplifies the decisions that need to be made, behaviour that is on the borderline between two
categories will always vex the classifier.
References
Barlow, D. H. and Hersen, M. (1984). Single case experimental designs: strategies for studying be-
havior change, 2nd ed., Pergamon Press, New York.
Bekoff, M. (1977). Three areas of classical ethology. pp 1-46 in Hazlett, B. A. (ed), Quantitative
methods in the study of animal behaviour, Academic Press, New York.