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.
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
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)
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
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