Experimental Design Flashcards
When a PREDICTABLE CHANGE in behavior (dependent variable or DV) can be reliably produced by the SYSTEMATIC MANIPULATION of some aspect of the individual’s environment (independent variable or IV).
The ANALYSIS dimension of the 7 dimensions of ABA.
AKA: Functional Relations; Control; Analysis
Experimental Control
4 Important Elements of Behavior
- ) Behavior is INDIVIDUAL (one person’s interaction with the environment)
- ) Behavior is CONTINUOUS (changes overtime)
- ) Behavior is DETERMINED (by functional relations it holds to other events)
- ) Behavior variability is EXTRINSIC to the organism (i.e., behavior change is the result of the environment; the IV, other people and/or uncontrolled factors)
6 Components of Experiments in ABA
- ) At least one Subject
- ) At least one Behavior (DV)
- ) At least one Setting
- ) At least one Treatment (IV)
- ) A measurement system and ongoing analysis of Data
- ) An experimental Design
All well-planned experiments begin with this.
A brief but specific statement of what the researcher wants to earn from conducting the experiment.
Can be in question or statement form.
Experimental Question
In this design the subject acts as his or her own control; does not mean that there is only one subject.
AKA: Single-case designs; Within-Subject Designs, Intra-Subject designs
ABA uses:
Single-Subject Designs
In this design repeated measures of the subject’s behavior during each phase of the study provide the basis for comparing experimental variables as they are presented or withdrawn in subsequent conditions (the presence and absence of IV).
The individual is exposed to each condition several times over the course of the study.
At least one subject: (Single Subject Designs)
Collateral Effects
A phenomenon in which the IV effects behaviors other than the targeted behavior.
Provide data patterns that can serve as controls for evaluating and replicating the effects of an IV.
Assess if any collateral effects occur.
Determine whether changes in the behavior of a person other than the subject occur during the course of an experiment and if such changes can explain changes in the subject’s behavior.
At least one behavior: (AKA: Dependent Variable - DV)
Control 2 sets of environmental variables to demonstrate experimental control:
- ) IV (present, withdraw, or vary its value)
- ) Extraneous Variables (prevent unplanned environmental variation)
Better to control in labs but in applied settings (homes, schools etc., it is harder to control the environment).
At least one (1) Setting
The particular aspect of the environment that the experimenter manipulates to find out whether it affects the subject’s behavior.
AKA: Independent Variable (IV); Intervention; Experimental Variable
At least one (1) Treatment
Observation and recording procedures must be conducted in a standardized manner.
Standardization involves every aspect of the measurement system ( from the behavior definition to scheduling of observations).
Behaviorists must detect changes in level, trend, and variability.
A measurement system and Ongoing analysis of Data
The particular arrangement of conditions in a study so that meaningful comparisons of the effects of the presence, absence, or different values of the IV can be made.
Experimental Design
The value of the IV is manipulated. Seeks to discover the differential effects of a range of values.
Ex. Various doses of medication are given in a course of a study.
Parametric Analysis
Two types of Experimental Designs:
- Nonparametric Design
2. Parametric Design
IV either present or absent during study.
HINT: Has the word ON in it (IV is either ON or OFF)
Ex. Medication is either given and then taken away in the course of a study.
Nonparametric Design
- Change only one variable at a time.
- Do not get locked into textbook designs.
- Select and combine designs that best fit the research question.
Important Rules of Experimental Designs
AKA: Behavioral Package
When multiple IVs are bundled into one program such as a token economy with praise and time-out.
Treatment Package
Looks at the effect of each part of the treatment package.
Used to determine the effective components of an intervention package.
Component Analysis
AKA: Stable State Responding
A pattern of responding that exhibits very little variation in its measured dimensional quantities over a period of time.
Provides the basis for BASELINE LOGIC.
Steady State Responding
Refers to the experimental reasoning inherent in single-subject experimental designs.
Entails 3 elements:
- ) Prediction
- ) Verification
- ) Replication
Each of these elements depends on an overall experimental approach called steady state strategy.
Baseline Logic
REPEATED EXPOSURE of a given condition while trying to eliminate extraneous influences on behavior and obtaining a stable pattern of responding before introducing the next condition.
Steady State Strategy
FUNCTION of Baseline Data
Serves as a control condition.
Does NOT imply the absence of intervention. It can be the absence of a specific IV.
BENEFITS of Baseline Data
- To use the subject’s performance in the absence of the IV as an objective basis for detecting change.
- To obtain descriptions of ABC correlations for the planning of an effective treatment.
- To guide us in setting the initial criteria for reinforcement.
- To see if the behavior targeted for change really warrants intervention.
4 Patterns of Baseline Data:
Hint: DAVS
D- Descending Baseline
A- Ascending Baseline
V- Variable Baseline
S- Stable Baseline
Descending Baseline:
Shows the behavior is already changing.
Generally, one should NOT implement the IV when baseline is descending; unless it is a functional skill that you are trying to increase and the decreasing trend shows the behavior worsening.
If descending baseline is due to a behavior you want to decrease you should wait because behavior is already improving.
Ascending Baseline:
Shows the behavior is already changing.
Generally, one should NOT implement the IV when baseline is ascending; unless it is a challenging behavior that you are trying to decrease and the increasing trend shows it is worsening.
If ascending baseline is due to a behavior you want to increase you should wait because behavior is already improving.
Variable Baseline
No clear trend
If one’s data is variable, wait it out and do not introduce the IV.
Variability is assumed to be due to environmental variables that are uncontrolled. If the IV is introduced here, you will not be able to tell if it changed the behavior or not.
You should try to control uncontrolled sources of variability.
No evidence of ascending or descending trend.
All of the values of the DV fall in a small range of values.
BEST way to look at the effects of the IV on the DV.
You can introduce the IV now.
Stable Baseline
3 Parts of Baseline Logic:
Hint: PVR
Prediction
Verification
Replication
After we PREDICT we:
AFFIRM
Inductive Logic:
- If the IV were not applied, the behavior (as indicated by baseline data would not change).
- The experimenter predicts the IV will change the behavior.
- If the IV controlling the DV (A), then the data path in the presence of the IV will show that the DV (B) has changed.
- When the IV is present, data show DV has changed (B is true)
- Thus, the IV is controlling the DV (thus, A is true).
Affirmation of the Consequent
The anticipated outcome of a presently unknown measurement.
Data should be collected until stability is clear.
Main question: Are data stable enough to serve as the basis for experimental comparison?
Prediction
Verifying a previously predicted level of baseline responding by termination or withdrawal of the treatment variable.
Verification
Is the essence of believability.
Shows reliability of behavior change; we can make it happen again.
Is accomplished by reintroducing the IV.
Replication
5 Main Experimental Designs
HINT: MC RAW
- Multiple Baseline
- Changing Criterion
- Reversal
- Alternating Treatments
- Withdrawal
- MOST WIDELY USED design.
- Highly flexible.
- Staggered implementation of the intervention in a step-wise fashion across BEHAVIORS, SETTINGS, & SUBJECTS.
- Do not have to withdraw a treatment variable in this design.
- When it is UNETHICAL or impractical to reverse conditions or when the behavior is irreversible use this design instead of a reversal design.
Multiple Baseline Design
A functional relation in this design requires change in behavior with the onset of the intervention.
Apply IV to behavior 1 when you can confidently predict that the behavior would remain the same in constant conditions.
If behaviors 2 & 3 remain unchanged after the application of the IV to behavior 1 , this verifies the prediction.
If the IV changes behavior 2 like it did behavior 1, the effect of the IV has been replicated.
The more replications, the more convincing the demonstrations.
Most commonly 3 to 5 tiers
Prediction, Verification and Replication in the Multiple Baseline Design
(How to Demonstrate Functional Relations with this Design)
Two or more different behaviors of the SAME SUBJECT.
Each subject serves as his/her own control.
After steady state baseline responding, the IV is applied to the first behavior while other behaviors are kept in baseline.
When steady state responding is reached for the first behavior, then the IV is applied to next.
Multiple Baseline Across Behaviors
A single behavior is targeted in two or more different settings or conditions.
After steady state baseline responding, the IV is applied to the first setting while other settings are kept in baseline.
When steady state responding is reached for the first settings, then the IV is applied to the next setting.
Multiple Baseline Across Settings
One target behavior for 2 or more subjects in the SAME SETTING.
After steady state baseline responding, the IV is applied to the first subject, while other subjects are kept in baseline.
When steady state responding is reached for the first subject, then the IV is applied to next subject.
MOST WIDELY USED MULTIPLE BASELINE GRAPH.
Multiple Baseline Across Subjects
2 Variations of Multiple Baseline Designs:
Both inherently weaker than traditional multiple baselines.
Can be used when extended baseline measurements is unnecessary, impractical, too costly or unavailable.
- ) Multiple Probe Design
2. ) Delayed Multiple Baseline Design
Analyzes relation between the IV and acquisition of skill sequences.
Instead of simultaneous baselines, probes provides the basis for determining if behavior change has occurred prior to intervention.
Multiple Probe Design
Initial baseline and intervention begin and subsequent baselines are added in a delayed or staggered fashion.
Effective when 1) reversal design is not possible, 2) limited resources preclude a full-scale design, and 3) when a new behavior, subject, or setting becomes available.
Limitation: Shorter baselines do not show interdependence of DVs.
Delayed Multiple Baseline Design