psych 310 chapter 10

Wha is a single subject research

• Type of quantitative research with studying in detail the behaviour of each small number of participant

• Usually group research

• Otfen the change from one condition to the next, depends on the participant’s behaviour

• Typically once the participant’s behaviour in one condition becomes fairly consistent

What are results of a generic single subject study

• DV is measured repeatedly over time at regular intervals

• The study is divided into distinct phases

• The participant is tested under one condition per phase

• Participant was tested in condition A, then condition B, the condition A again.

• Reversal design

What are reversal designs

• Basic form of single subject

• Researcher measures DV in 3 phases: baseline before, after treatment, return to baseline

What is a baseline

Beginning phase of an ABA design which acts as control before any treatment given

What is multiple baseline designs

• Two potential problems with the reversal design

• If a treatment is working, it may be unethical to remove it

• The DV may not return to baseline when the treatment is removed

• One solution is to use a multiple baseline design

What is Multiple-Baseline Designs: Multiple-Baseline Design Across Participant

• Baseline established for each participant and then introduced at different times for each participant

• If the DV changes when the treatment is introduced for one participant, it might be coincidence

• If the DV changes when the treatment is introduced for multiple participants at different times then it is unlikely to be a coincidence

Multiple-Baseline Designs: Multiple-Baseline Design Across Settings

• Multiple baselines are established for the same participant but in different settings

• Baseline on DV established in setting 1 and setting 2

• Treatment applied in setting 1, then applied later on in setting 2

• If the DV changes after the treatment is introduced in each setting, then this gives the researcher confidence that the treatment is responsible

Multiple-Baseline Designs: Multiple-Baseline Design Across Behaviors

• Multiple baselines established for the same participant but for different DVs, and the treatment is introduced at a different time for each DV

• If the DV changes after the treatment is introduced, it is unclear if the treatment caused the change

• But if both DVs change after the treatment is introduced, especially when the treatment is introduced at two different times, then it seems much clearer that the treatment was responsible

What is a multiple treatment reversal design

Baseline phase follow by separate phases in which treatment introduced

What is multiple baseline design

• Two potential problems with the reversal design

• If a treatment is working, it may be unethical to remove it

• The DV may not return to baseline when the treatment is removed

• One solution is to use a multiple baseline design

What is a trend

Gradual increase or decrease in DV across observations

What a level

Changes in levels of the from condition to condition DV

What is latency

The time it takes for DV to begin changing for change in conditions

Why is alternating treatment design

2+ treatment are alternated quickly on a schedule

What is a visual inspection

• Plotting individual participants’ data

graphically

• Looking at those data then Making judgments whether the IV had an effect on the DV

Why is percentage of non-overlapping data PND

• Percentage of responses in the treatment condition that are more extreme than the most extreme response in baseline

• The greater the percentage of non-overlapping data, the stronger the treatment effect