This document discusses single subject research design. It defines single subject design and describes its key characteristics. These include having only one independent variable changed at a time between baseline and intervention conditions. The length of conditions and number of data points in each is important to establish trends. Graphs demonstrate how degree and speed of change between conditions and a return to baseline levels impact internal validity. The number of baselines in a multiple baseline design also influences conclusions that can be drawn. Replication across subjects is important to strengthen external validity of single subject findings.

1. SINGLE SUBJECT
RESEARCH
PREPARED FOR:
DR JOHAN @ EDDY LUARAN
PREPARED BY:
AFZA ARRMIZA BINTI RAZIF [2013697158]
HANIFAH BINTI RAMLEE
IZYAN NADHIRAH BINTI WAHID
MAIZATUL AKMAL BINTI ZULKIFLI

2. DEFINITION
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3. SINGLE SUBJECT DESIGN
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4. CHARACTERISTIC
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7. Figure 14.2 A-B Design
As you can see, five measures were taken before the
intervention and five more during the intervention. Looking at
the data in figure 14.2, the intervention appears to have been
effective. The amount of responsiveness after the
intervention increased markedly.

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18. Threat to Internal Validity in SingleSubject Research
It involve the :
 The length of the baseline and intervention conditions
 The Number of Variables Changed When Moving from One
Condition to Another
 The Degree and Speed of Change
 The Return to Baseline Level
 Independence of Behaviour
 Number of Baselines

19. CONDITION
LENGTH
 Refers to how long the
baseline and intervention
conditions are in effect.
 The number of data points
gathered during a conditions.
 Minimum three of data point
to establish a clear pattern or
trend.
 As a hypothesis,in a certain
period or condition of
length,the researcher need
to gathered enough data as it
will establish the clear
pattern

20.  Figure 14.10 (a)
 Figure 14.10 (b)

21.  NUMBER OF
VARIABLES
CHANGED WHEN
MOVING FROM ONE
CONDITION TO
ANOTHER
 Only one variable should be
changed at a time when
moving from one condition
to another
 When analyzing a single –
subject design,it always
important to determined
whether only one variable
at a time has been changed

22. DEGREE AND
SPEED OF
CHANGE
 In single-subject
research,the stability is
important
 The data change at the
time the intervention
condition is implemented
influenced the stability of
baseline
(when the independent
variable is introduced or
removed)

23.  Figure 14.11(a)
 Figure 14.11(b)

24.  Figure 14.11(c)

25. RETURN TO
BASELINE
LEVEL
 The subject’s behaviour did
not return to the original
baseline level suggest that
the one or more extraneous
variable may have
produced the effects
observed during the
intervention condition

26. Differences in Return to Baseline
Conditions
 Figure 14.12(a)
 Figure 14.12(b)

27. NUMBER OF
BASELINES
 In order to have a multiple –
baseline design,researcher
must have at least two
based line
 Baseline begin at same
time,the intervention occur
in different time
 More baseline and
intervention will lead to
invalid conclusion

28.  NUMBER OF
BASELINES
 The greater number of
baselines,the greater the
probability that the intervention
is the cause of any change in
behaviour
 The more baselines,there
are,the longer the later
behaviours must remain in
baseline
 The fewer the number of
baseline,the less likely we can
conclude that is the intervention
rather than some other variable
that causes any change in
behaviour

29. 
CONTROL OF
THREATS TO
INTERNAL
VALIDITY IN
SINGLE-SUBJECT
RESEARCH
Single-Subject designs are
most effective in controlling
for :
 Subject characteristics
 Mortality
 Testing
 History

30. EXTERNAL
VALIDITY IN
SINGLE-SUBJECT
RESEARCH:THE
IMPORTANCE OF
REPLICATION
 Single subject studies are
weak when it comes to
external validity
 Total rely on replicationsacross individual instead of
groups
 The result worthly of
generalization