Experimental design tends to trip lots of people up. Here’s an exam trick for breaking down questions about experimental design. But first, a caveat: please take the time to study and understand the main designs. While this trick is going to help you dissect questions, maybe even answer some questions correctly, it is not enough to make you fluent.

Visualize and memorize three defining features of each design: How many independent variables does the design test? How many dependent variables does the design measure? What is this design used to do? That’s easy enough. Then be sure to include these features on your whiteboard, even during practice tests.

• Reversal or withdrawal designs: one IV, one DV. Used for proving that the IV is responsible for the changes to the DV.
• Multi-element design: two to four IVs, one DV. Used for quickly comparing the effects of several procedures on one behavior. Also, this is the design that we use for functional analysis.
• Multiple baseline design: one IV, two or more DVs. Use for looking at the generalizability of one IV across the different behaviors, different subjects, or different behaviors of one subject, or the different settings in which a behavior might occur.
• Multiple treatments reversal: one or more IVs, one DV. Use for proving and comparing the effectiveness of more than one IV.
• Changing criterion design: one IV, one DV. Use for showing how criteria can control responding.

Now, make sure to take some time to understand and visualize these features. When you have an experimental design question, break down the question by plugging in these features: How many IVs? How many DVs? And what is the purpose of the experiment in the scenario? Chances are, considering the number of IVs and DVs, and the purpose of the experiment will help you get closer to a correct answer.

Related Content

Sequence effects

A confounding effect on a subject’s behavior in a given condition that results from the subject’s experience with a previous condition.

Repeated reversals design

A variation of the reversal design that includes replication, in which responding is reversed to a level obtained in a previous condition by alternating between specific independent variables and baseline…

Nonconcurrent multiple baseline across participants design

A variation of the delayed multiple baseline design in which the baselines are so delayed that there is no overlap between them, like a series of AB designs across participants.

Multiple baseline design

An experimental design in which the effect of one independent variable is measured and evaluated within and across combinations of two or more subjects, behaviors, or settings.

Multiple treatment interference

In an experimental design that requires the implementation of more than one independent variable to one subject, the outcome of one treatment may be influenced by the effect of another.

Multiple probe design

A variation of the multiple baseline design that uses intermittent measurement or probes instead of consecutive measures to evaluate the effect of one independent variable within and across combinations of…

Multiple treatment (reversal) design

A variation of the reversal design in which multiple treatments are alternated in different phases and compared to baseline and/or each other.

NCR reversal technique

A variation of the reversal design in which noncontingent reinforcement is used as the control condition and contrasted against contingent reinforcement. Responding is reversed to a level obtained in a…

Multielement design

An experimental design in which two or more independent variables are presented in rapidly alternating succession, and the differential effects of each independent variable on the target behavior are measured.

Irreversibility

A behavior for which the effects of treatment cannot be undone. Therefore, it cannot return to a baseline level of responding when an independent variable is removed.

DRO/DRI/DRA reversal technique

A variation of the reversal design in which DRO, DRA, or DRI are used as the control condition and contrasted against each other. Responding is reversed to a level obtained…

Delayed multiple baseline design

A variation of the multiple baseline design in which all of the baselines do not begin at the same time, instead additional participant baselines are added to the study as…

Changing criterion design

An experimental design in which an initial baseline phase is followed by a series of treatment phases consisting of successive, stepwise, and gradually changing criteria for which reinforcement or punishment…

BAB reversal design

A three-phase variation of the reversal design that begins with the treatment phase first, followed by the baseline phase, after which responding is reversed to a level obtained in the…

Dana Do's: Can Changing Criterion Design be Used to Evaluate Shaping Programs?

Can can a changing criterion design be used to evaluate shaping programs? Well, PTB founder Dana Meller says, it depends.

Reversal design

Any experimental design in which responding is reversed to a level obtained in a previous condition by alternating between specific independent variables and baseline conditions.

Let's Break Down a BCBA® Mock Exam Question: Ethical Considerations in Experimental Design

Test your understanding of ethical considerations in experimental designs with PTB co-founder Dana Meller. Let's review a BCBA® mock exam question about reversal design and the nuances and concerns associated with this experimental setup. Refer to BCBA® Task List (5th ed.) Section D-5: Use single-subject experimental designs (e.g., reversal, multiple baseline, multielement, changing criterion).

The Most Utilized Experimental Design for Generalization Effects

Learn what the most utilized experimental design is for generalization effect. PTB co-founder Dana Meller shares this design's key features and benefits, allowing us to assess the effects of an independent variable across various settings, subjects, and behaviors. Refer to BCBA® Task List (5th ed.) Section D-5: Use single-subject experimental designs (e.g., reversal, multiple baseline, multielement, changing criterion).

CON Artist Captured! Unmasking the CONfounding Variable of the Alternating Treatments Design

PTB co-founder Dana Meller hones your experimental design skills with a focus on the alternating treatments design's confounding variable. Refer to BCBA® Task List (5th ed.) Section D-5: Use single-subject experimental designs (e.g., reversal, multiple baseline, multielement, changing criterion).

Breaking Down a Mock BCBA® Exam Question: Reversal Design Variations With Only One Reversal

Test your Experimental Design skills with PTB co-founder Dana Meller as she reviews and breaks down a mock exam question about reversal design variations that display only one reversal. Included is a description of A-B-A, B-A-B, and A-B-A-B reversal designs. Refer to BCBA® Task List (5th ed.) Section D-5: Use single-subject experimental designs (e.g., reversal, multiple baseline, multielement, changing criterion).

Shortcuts to Understanding the Basics Behind Each Experimental Design

Experimental design causes a lot of anxiety. PTB co-founder Dana Meller shares a few shortcuts to help on exam day, eliminating some answer options but also, more importantly, give you a head start on understanding the basics behind each design.

The Proof of Function is in the Reversal Design Pudding

PTB co-founder Dana Meller puts your understanding of experimental design to the test. What are the critical phases required for a successful and robust experimental setup. Refer to BCBA® Task List (5th ed.) Section D-5: Use single-subject experimental designs (e.g., reversal, multiple baseline, multielement, changing criterion).

Breaking Down a Mock BCBA® Exam Question: Identify a 3-Phase Reversal Experimental Design

Test your Experimental Design skills with a breakdown of a BCBA® mock exam question about the identification of a three-phase experimental design. Included is a detailed comparison between four different reversal designs: ABC reversal, ABA reversal, BAB reversal, and ABAB reversal. As a bonus, Dana also provides examples of instances in which each of the reversal designs would be implemented. Refer to BCBA® Task List (5th ed.) Section D-5: Use single-subject experimental designs (e.g., reversal, multiple baseline, multielement, changing criterion).

Test your ABA Terminology ➠ Identify This Experimental Design Scenario

Test your ABA terminology with PTB co-founder Dana Meller as she offers guidance to identify the specific experimental design relating to a scenario. Refer to BCBA® Task List (5th ed.) Section D-5: Use single-subject experimental designs (e.g., reversal, multiple baseline, multielement, changing criterion).

Dana Do's: A Trick to Help Dissect BCBA® Exam Questions on Experimental Designs

Experimental design tends to trip lots of people up. Here's an exam trick from Dana Meller that will help you breaking down questions on the exam.

Dana Do's: 1-Minute Experimental Design Test Hack (you still have to study it though)

PTB co-founder Dana Meller shares a huge secret to help break down experimental design questions. BCBA® Task List (5th ed.) Section D-3: Identify the defining features of single-subject experimental designs.

Dana Do's: Importance of Experimental Design Fluency

PTB co-founder Dana Meller talks about the importance of being fluent in experimental designs, not just to pass the exam, but to be a good clinician as well. Ref Section D-3: Identify the defining features of single-subject experimental designs (e.g., individuals serve as their own controls, repeated measures, prediction, verification, replication).

Dana Do's: The Distinction Between Analysis Types and Experimental Designs

What’s the difference between parametric, component, and comparative analyses? And what do experimental designs have to do with it? PTB founder Dana Meller clears up the confusion with a deep dive into analysis variations.

Dana Do's: What's the Difference Between Continuous and Discontinuous Measurement?

It’s all too easy to mix up continuous and discontinuous measurement procedures. Need some help discriminating between the two? Get clarity with help from PTB founder Dana Meller.

Interobserver agreement (IOA)

A measurement of the degree to which two or more observers report the same values when observing and collecting data for the same behaviors/events.

Dana Do's: Tips for Test Questions About Functional Analysis

Tripped up trying to make correct discriminations when it comes to functional analysis? PTB founder Dana Meller has some tips to help you answer those tricky exam questions.

Dana Do's: Six Direct Assessment Methods

Looking to review direct assessment methods? PTB founder Dana Meller gets right to it with this quick explainer.

Dana Do's: Exploring the Four Types of Reinforcer Assessments

PTB founder Dana Meller discusses reinforcer assessments, which should not be confused with stimulus preference assessments.

Dana Do's: Nine Considerations for Prioritizing Target Behaviors

PTB founder breaks down each of the nine considerations for prioritizing target behaviors.

Dana Do's: Why IOA Math Should Not Intimidate You

PTB co-founder takes some of the fear out of the interobserver agreement math with simple tips that can help narrow your discrimination.

10 Positive Effects From Prioritizing Self-Care

Self-care. It’s a bit of a broad term, and a total buzzword these days. It’s often used in the context of bubble baths and “unplugging.” But, at its core, self-care is about more than just “me-time.” It’s about taking care of yourself in a way that works best for you and your lifestyle.

Dana Do's: How to Know if Your Study Activities are Effective

How do you know if your BCBA® study activities are effective? PTB co-founder Dana Meller shares some key analysis that may help BCBA® exam candidates assess efficacy.

Dana Do's: Careful About Getting Creative With Mock Exams

PTB co-founder cautions candidates about using the actual BCBA® exam as a mock exam, listing all the reasons why you might want to reconsider getting creative with your mock exam prep experience.

Dana Do's: Warning. Be Careful of Extremes.

PTB co-founder Dana Meller sends an important warning for test takers. Watch out for extremes in exam questions and answer options.

Dana Do's: How to Use Mock Exams in Your Study Plan

I was recently asked if mock exams are useful in predicting how someone will do on the actual big exam. And, is repeating the same mock exam an effective study…

Dana Do's: How to Define the Markers of Trustworthy Measurement

PTB co-founder goes into the three factors that define trustworthy measurement-- "validity", "reliability" and "accuracy". But what's the difference between each? Dana explains.

Dana Do's: How to Decipher the Many Forms of Validity

It's particularly meaningful to be able to tell validity, social validity, internal and external validity apart. PTB co-founder Dana Meller has some tips to do just that.

Dana Do's: How to Discriminate Dependent vs. Independent Variables If You're Not a Researcher

Not a researcher? How about some help discriminating between dependent and independent variables. PTB co-founder Dana Meller offers a few tips to make that distinction on the BCBA® exam.

Breaking Down a BCBA® Mock Exam Question: Winning Measurement System to Record Client Tolerance to Losing

Let's review and break down a BCBA® mock exam question about measurement techniques in ABA, specifically percentage of opportunity. PTB co-founder Dana Meller explains how to calculate the percentage of opportunities where the behavior is exhibited and why this method is superior to rate, count, and interval recording in certain situations. Refer to BCBA® Task List (5th ed.) Section C-3: Measure occurrence (e.g., count, frequency, rate, percentage).

ABA Terminology Break Down ➠ Indicators of Trustworthy Measurement

What are the three indicators of trustworthy measurement in ABA? PTB co-founder Dana Meller explains and why they ensure data accuracy and reliability. Refer to BCBA® Task List (5th ed.) Section C-8: Evaluate the validity and reliability of measurement procedures.

MiniBig

 

PTB MiniBig: Fast, Flexible, and Focused Exam Prep

The PTB MiniBig enables BCBA® exam prep candidates to tailor their study needs by popping in on single sessions of the intensive PTB Big Exam Prep Workshop. Each 3.5-hour session, focused on specific sections of the Task List, includes a mock exam followed by real-time, live, interactive feedback and access to live session replays, without committing to the full workshop.

Test your ABA Terminology ➠ Functional Assessment Procedures

Focusing on ABC data collection, PTB co-founder Dana Meller discusses functional assessment procedures. Dana explains how to generate mathematical probabilities for target behaviors based on specific antecedents and consequences, providing a step-by-step guide to quantitatively analyzing the gathered information. Refer to BCBA® Task List (5th ed.) Sections F-7: Conduct a descriptive assessment of problem behavior and F-9: Interpret functional assessment data.

Test Your Descriptive Assessment Skills ➠ ABC Recording Methods

Get a comprehensive overview of ABC Recording Methods. PTB co-founder Dana Meller breaks down the two types, along with their differences, benefits, and practical applications. Refer to BCBA® Task List (5th ed.) Sections F-7: Conduct a descriptive assessment of problem behavior; and F-9: Interpret functional assessment data.

Test your ABA Terminology ➠ Cumulative Record Calculations

PTB co-founder Dana Meller reviews a question about using cumulative records and their significance in behavior analysis. Learn how to utilize cumulative graphs to track behavior over specific time periods and measure and calculate response rates for insightful data analysis. Refer to BCBA® Task List (5th ed.) Section C-11: Interpret graphed data.

Test your ABA Terminology ➠ Identify the Measurement System in This Scenario

Test your measurement, data display, and interpretation knowledge with PTB co-founder Dana Meller as she discusses one specific measurement system that measures the effect of the behavior after its occurrence. Here, Dana details the two ways someone could implement this type of measurement system, provides examples of scenarios and a variety of corresponding measurement methods, and highlights some of the pros of utilizing this type of measurement system. Refer to BCBA® Task List (5th ed.) Section C-2: Distinguish among direct, indirect, and product measures of behavior.

Break Down a Mock BCBA® Exam Question: Interobserver Agreement (IOA) Facts & Rules to Live By

Test your Measurement, Data Display, and Interpretation skills with PTB co-founder Dana Meller as she reviews a BCBA® mock exam question about several #interobserveragreement (IOA) facts, with rules to live by. Here, Dana highlights a variety of important IOA benefits, as well as IOA percentage of agreement criteria details and the different reporting options. Refer to BCBA® Task List (5th ed.) Section C-8: Evaluate the validity and reliability of measurement procedures.

Test your ABA Terminology ➠ Pivotal Behavior vs. Behavior Cusp

Test your behavior assessment knowledge with PTB co-founder Dana Meller as she compares and contrasts pivotal behavior vs. behavior cusp, providing several corresponding examples of each, as they relate to identifying the target behaviors that need prioritization for treatment. Refer to BCBA® Task List (5th ed.) Section F-3: Identify and prioritize socially significant behavior-change goals.

IOA Mini Quiz

Math can be daunting, but practice can help. You don’t have to be a math whiz to master the Interobserver Agreement formulas. Get more practice and gain confidence with the PTB IOA Mini Quiz. Updated for the 6th Edition Test Content Outline, the PTB IOA Mini Quiz features a new interactive format that simulates the test experience. Thirty fill-in-the-blank questions cover all 9 IOA formulas. Optional hints included with each quiz question assist you with the correct formula along the way. Check your work and collect data on your performance with the detailed score report. 

Test your ABA Terminology ➠ Interpret Descriptive Assessment Data

Test your knowledge of interpreting descriptive assessment ABC data with PTB co-founder Dana Meller. Here she discusses conditional probability, including the rules that apply, and provides a step-by-step example using the calculation formula and how to report these data. Refer to BCBA® Task List (5th ed.) Sections F-7: Conduct a descriptive assessment of problem behavior; F-9: Interpret functional assessment data.

Test your ABA Terminology ➠ Derivative Measures Explained

Put your knowledge of occurence measurement to the test with PTB co-founder Dana Meller as she discusses the two types of derivative measures, and each of their defining features and applications. Dana focuses on the derivative measure used for comparing two or more procedures, teaching clients new skills, evaluating mastery over a class of concepts, and the various measurement methods. Refer to BCBA® Task List (5th ed.) Section C-6: Measure trials to criterion.

Experimental Validity: The Relationship between Behavior Change & Independent Variables

PTB co-founder explains the different types of validity in ABA. Refer to BCBA® Task List (5th ed.) Section D-2: Distinguish between internal and external validity.

Test your ABA Terminology ➠ Indicators of Trustworthy Measurement

Test your knowledge with PTB co-founder Dana Meller as she explains the specific indicator of trustworthy measurement that corresponds with repeated measurement yielding the same result. Included is a description of all three indicators of trustworthy measurement validity, accuracy, and reliability. Refer to BCBA® Task List (5th ed.) Section C-8: Evaluate the validity and reliability of measurement procedures.

Breaking Down a Mock BCBA® Exam Question: Understanding Equal-Interval Graphs & Logarithmic Scales

Test your knowledge of ABA graphs with PTB co-founder Dana Meller as she reviews a BCBA® mock exam question about equal-interval graphs, exploring their unique properties. Included, Dana explains the concept of proportional values and highlights the graph(s) which operate on a logarithmic scale, offering a different perspective on changes in behavior. Refer to BCBA® Task List (5th ed.) Sections C-10: Graph data to communicate relevant quantitative relations (e.g., equal-interval graphs, bar graphs, cumulative records); C-11: Interpret graphed data.

Test your ABA Terminology ➠ Confounding Threats to Internal Validity

Test your knowledge of measurement confounds with PTB co-founder Dana Meller as she discusses one of the four types of threats to internal validity, with corresponding examples. Refer to BCBA® Task List (5th ed.) Section C-8: Evaluate the validity and reliability of measurement procedures.

Breaking Down a BCBA® Mock Exam Question: It's the IOA Battle Royal. Which Formula Gets Knocked Out?

Sharpen your measurement skills with PTB co-founder Dana Meller as she reviews a BCBA® mock exam question about IOA and helps explain the different formulas used for time sampling measurements. Dana covers four IOA formulas: Interval-by-Interval, Scored Interval, Trial-by-Tial, and Unscored Interval; and highlights key considerations and pitfalls associated with each. BCBA® Task List (5th ed.) Section C-8: Evaluate the validity and reliability of measurement procedures.

Test your ABA Terminology ➠ Fundamental Properties of Behavior Change

Test your ability to interpret graphed data with PTB co-founder Dana Meller. Here she explains the three fundamental properties of behavior change, focusing on one specific property akin to an average or median. Included are descriptions of level, trend, variability, and the y-axis. Refer to BCBA® Task List (5th ed.) Section C-11: Interpret graphed data.

Breaking Down a BCBA® Mock Exam Question: The #1 Threat to Accuracy and Reliability

Test your measurement knowledge with PTB co-founder Dana Meller as she reviews a BCBA® mock exam question about the key indicators of trustworthy measurement, revealing the most significant threat facing accuracy and reliability. Dana provides insight into the distinctions between reliability, validity, and accuracy and how they relate to measurement. BCBA® Task List (5th ed.) Section C-8: Evaluate the validity and reliability of measurement procedures.

Threats to Validity Exposed: When Misleading Data Plays Tricks on Your Perception

Test your knowledge of measurement procedures with PTB co-founder Dana Meller as she explains, in detail, one of the threats to validity with several corresponding examples. Dana also shares a clever memorization study tip that will help you on the Big exam. Refer to BCBA® Task List (5th ed.) Section C-8: Evaluate the validity and reliability of measurement procedures.

Let's Break Down a BCBA® Mock Exam Question: Key Elements of Baseline Logic for Multiple Baseline Design (D-3)

PTB co-founder Dana Meller breaks down a BCBA® mock exam question about baseline logic for a multiple baseline design across behaviors. Dana explains the significance of replication in providing more convincing evidence of a functional relationship and how to make scientific justifications using baseline logic in various designs. Refer to BCBA® Task List (5th ed.) Section D-3: Identify the defining features of single-subject experimental designs (e.g., individuals serve as their own controls, repeated measures, prediction, verification, replication).

Dana Do's: All the Validities in ABA, Explained

PTB founder Dana Meller helps connect each of the validities to the validity of this explanation.

Let's Break Down a BCBA® Mock Exam Question: Identifying Measurement Confounds in Experimental Design

PTB co-founder Dana Meller breaks down a BCBA® mock exam question that explores the difference between measurement confounds and subject confounds, how they relate to threats to internal validity in ABA research. Refer to BCBA® Task List (5th ed.) Section D-2: Distinguish between internal and external validity.

Experimental Design Terminology ➠ The Baseline Logic Blueprint & the Sum of Its Parts

Join PTB co-founder Dana Meller as she discusses baseline logic in single-subject experimental designs. Dana breaks down the four essential elements of baseline logic and how these elements play a crucial role in demonstrating experimental control and confirming the effectiveness of interventions. Refer to BCBA® Task List (5th ed.) Section D-3: Identify the defining features of single-subject experimental designs (e.g., individuals serve as their own controls, repeated measures, prediction, verification, replication).

Dance the Axes Tango: Assessing Intervention Effectiveness on the Dynamic Data Graph Floor

Sharpen your experimental design skills and explore how independent variables influence behavior. PTB co-founder Dana Meller explains how to decipher graphical representations of data and understand the roles of the y-axis and x-axis. Refer to BCBA® Task List (5th ed.) Section D-1: Distinguish between dependent and independent variables.

Let's Break Down a BCBA® Mock Exam Question: Analyzing the Fundamental IV & BehaviorChange Relationship

Hone your experimental design skills through review of a BCBA® mock exam question. PTB co-founder Dana Meller breaks down the crucial aspect of experiments—how they demonstrate changes in behavior attributed to the independent variable. Refer to BCBA® Task List (5th ed.) Section D-2: Distinguish between internal and external validity.