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

DEFINITION

• A research of collecting data from a few individual.

For example: researcher who wish to study children who

suffer from multiple disability for example who are both deaf

and blind may have only a small number of children available

to them.

• Number of available is six or less. It would make little sense

to form two groups of three each in such an instance.

• Each child would probably need to be observed in great

detail.

SINGLE SUBJECT DESIGN

• Adaptations of the basic time-series design shown the

previous chapter .

• Data are collected and analyzed for only one subject at a

time.

• Commonly used to study the changes in behavior an

individual exhibits to an exposure to an intervention or

treatment of some sort.

CHARACTERISTIC

The Graphing Of Single-Subject Design

• Primarily use line graphs to present their data and to illustrate

the effects of a particular intervention or treatment.

• Vertical axis usually display the dependent (outcome)

variable.

• Horizontal axis used to indicates sequence of time.

• Figure 14.1 presents an illustration of such a graph. The

dependent (outcome) variable is displayed on the vertical

axis (the ordinate, or y-axis).

• The horizontal axis (the abscissa, or x-axis) is used to

indicates sequence of time, such as sessions, days, week,

trials or months.

The A-B Design

• The basic approach of researchers using an A-B design is to

collect data on the same subject, operating as his or her own

control, under two conditions or phases.

• The first condition is the pretreatment condition called

baseline period is identified as A. The baseline is extremely

important in single-subject research since it is the best

estimate of what would have occurred if the intervention were

not applied.

• Once the baseline condition has been established, a

treatment or intervention condition, identified as B.

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.

The A-B-A Design

A-B-A design will able researcher to simply adding another

baseline period.

This may improves the design considerably.

The A-B-A-B Design

• Two baseline period are combined with two treatment

periods.

• This further strengthens any conclusion about the

effectiveness of the treatment.

• It permits the effectiveness of the treatment to be

demonstrated twice.

• In fact, the second treatment can be extended indefinitely if a

researcher so desires.

The B-A-B Design

• In such cases, a B-A-B design may be used which involves

a treatment followed by a baseline and also followed by a

return to the treatment.

• It usually according to times when an individual’s behaviour

is so severe or disturbing.

The A-B-C-B Design

• A further modification of the A-B-A design.

• C refers to a variation of the intervention in the B condition.

• In the first two condition, the baseline and intervention data

are collected.

• During the C condition, the intervention is changed to control

for any extra attention the subject may have received during

the B phase.

• The C condition, therefore, might be praise given no matter

how the subject responds.

Multiple-Baseline Design

• Alternative for A-B-A-B design

• Used when it is not possible or ethical to withdraw a

treatment and return to the baseline condition.

• When using this design, researchers do more than collect

data on one behavior for one subject in one setting.

• They collect on several behaviors for one subject, obtaining

a baseline for each during the same period of time.

Threat to Internal Validity in Single-

Subject ResearchIt 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

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

Figure 14.10 (a)

Figure 14.10 (b)

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

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)

Figure 14.11(a)

Figure 14.11(b)

Figure 14.11(c)

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

Differences in Return to Baseline

Conditions

Figure 14.12(a) Figure 14.12(b)

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

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,thereare,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

CONTROL OF

THREATS TO

INTERNAL

VALIDITY IN

SINGLE-SUBJECT

RESEARCH

Single-Subject designs are

most effective in controlling

for :

Subject characteristics

Mortality

Testing

History

EXTERNAL

VALIDITY IN

SINGLE-SUBJECT

RESEARCH:THE

IMPORTANCE OF

REPLICATION

Single subject studies are

weak when it comes to

external validity

Total rely on replications-

across individual instead of

groups

The result worthly of

generalization