Interlaza

Interlaza Prep · Exam-prep course

Practice for the BCBA® exam, with the reason behind every answer

Interlaza Prep is a course of original multiple-choice questions written for the BCBA® Test Content Outline. After each answer you see why it is right, or why yours does not fit, and the topics you miss come back until they hold.

practice questions
1,033
content areas
9
topics
104

Covers all 9 areas of the BCBA® Test Content Outline (6th ed.)

Try it free See how it works

Try a sample free, without an account. The full course is free until 30 November 2026; from 1 December, €9 a month with a 14-day free trial.

Illustration: a candidate studies at her desk with a notebook and Interlaza Prep open on a phone.

Getting started

Start in three steps

  1. 1. Open Interlaza Prep

    Go to interlaza.app/prep. You can try it straight away, without an account, on a sample of the questions.

    Open the course

  2. 2. Answer your first 5 questions

    A short first pass through different areas, corrected one question at a time. It takes a few minutes and starts pointing your practice where it is needed.

  3. 3. Keep going with an account

    Sign up with your email or a Google account to open the whole bank, the mock exam and the lessons, and the answers you already gave stay with you. Free until 30 November 2026. From 1 December: €9 a month with a 14-day free trial, or included in the Professional, Researcher and Institution plans.

    Create your account

How it works

Answer, see why, and come back to what you missed

Where a topic has a lesson, learn it in a short lesson, then practice it. Every session runs the same loop, and the course decides what comes next from your own answers.

  1. Answer

    Pick an option and say how sure you are: Sure, Not sure or Guessing.

  2. See why

    You see the correct answer and why it is correct. If you missed, you also see why your option does not fit and which confusion it points to.

  3. Come back to it

    A topic you missed returns a few questions later, and again on another day, with a new question. Once a topic is consolidated, its reviews are spaced out so it is not forgotten.

Three-panel illustration: she answers a question on her phone, reads the explanation, and later the topic comes back for review.

Three ways to practice

  • A 5-question start

    Your first session: questions from different areas, corrected after each one.

  • Practice by area

    Choose one of the 9 areas, or a single topic, 10 questions at a time. Pending mistakes, reviews due and weak topics come first.

  • Timed mock exam

    50 or 185 questions with a timer, corrected at the end. The 185-question mock lasts 4 hours, like the real exam, and questions are split by area the same way.

See where you stand

  • Mastery by topic

    An estimate for each topic that updates with every answer, with the 95 % mastery line marked.

  • Confidence and accuracy

    How often you are right when you mark an answer "Sure". Errors made while sure are the first ones to review.

  • Upcoming reviews

    How many reviews are due in the next 14 days, so you can plan your study time.

What it looks like

Questions are always in English; the interface and the explanations are available in English and Spanish.

Interlaza Prep home screen on a phone: a button to start with 5 questions and the size of the question bank.
The first screen: one button to start, and the size of the bank.
A corrected question on a phone: the correct option in green, the chosen option in amber, the confusion named and the reason the answer does not fit.
After an answer: the correct option, your confusion named, and why your answer does not fit.
Returning home screen on a phone: the next practice and a list of errors to re-check today.
Coming back: your next practice and what to review today.
A mock-exam question on a computer, with the timer and the confidence buttons.
Mock exam: the timer runs and every question asks how sure you are.
The progress screen on a computer: mastery by topic, activity over the last weeks, and confidence against accuracy.
Progress: mastery by topic, your activity, and confidence against accuracy.

What it covers

Every area of the outline

Practice questions per area, counted from the course as it is today. Under each area, the number of topics and about how many scored questions it carries in the exam.

  • A Behaviorism and Philosophical Foundations 48 questions

    5 topics · ~8 in the exam

  • B Concepts and Principles 227 questions

    24 topics · ~24 in the exam

  • C Measurement, Data Display, and Interpretation 123 questions

    12 topics · ~21 in the exam

  • D Experimental Design 84 questions

    9 topics · ~13 in the exam

  • E Ethical and Professional Issues 117 questions

    12 topics · ~22 in the exam

  • F Behavior Assessment 89 questions

    8 topics · ~23 in the exam

  • G Behavior-Change Procedures 182 questions

    19 topics · ~25 in the exam

  • H Selecting and Implementing Interventions 84 questions

    8 topics · ~20 in the exam

  • I Personnel Supervision and Management 79 questions

    7 topics · ~19 in the exam

Before you start

  • Practice results do not predict or guarantee passing the BCBA® exam. Use them to decide what to study next.
  • Interlaza Prep is independent. It is not affiliated with or endorsed by the BACB®.
  • Every question is original, written for this course. None is a real exam question or a "recalled" one.
Illustration: an Instructor sits beside a young child who touches a matching picture on a tablet, while a parent watches.

After you pass

The same method, with the children you work with

Interlaza is an app for match-to-sample training with young autistic children, from 18 to 36 months. Each session adapts to the child: Bayesian Knowledge Tracing estimates what has been learned and decides what to practice next, and help fades as the child responds correctly.

Several things you used in Prep work the same way there: an error is re-checked with a new example, mastered skills come back for spaced review, and mastery is estimated from the answers themselves. The Instructor gets the trial-by-trial data to read and decide.

See Interlaza for Instructors

Questions

Is it free?

You can always try a sample of the questions for free, without an account. The full course is free with an Interlaza account until 30 November 2026. From 1 December 2026 it costs €9 a month, with a 14-day free trial, and it is included at no extra cost in the Professional, Researcher and Institution plans.

Do I need an account?

Not to try it: without an account you practice on a sample of the questions. The whole bank, the mock exam and the lessons need an Interlaza account (and, from 1 December 2026, the Prep subscription or a Professional, Researcher or Institution plan). Your answers are saved on your device; once signed in, you can also turn on a copy in your account from the Progress screen so they follow you to another device.

Are the questions in English?

Yes. The BCBA® exam is given in English, so every question is in English. The interface and the explanations are available in English and Spanish, and you can switch an explanation to the other language.

Does it guarantee that I pass?

No. Practice results do not predict or guarantee your exam result. They show which topics you have worked on and where your errors are.

What about the RBT® exam?

Yes. The same course now also covers the RBT® exam (RBT Test Content Outline, 3rd ed.): original questions for all 6 areas, practice by area and a timed 85-question mock exam. Open interlaza.app/prep and choose RBT®.

Can I use it on my phone?

Yes. It runs in the browser on a phone, tablet or computer, with nothing to install.

Start with 5 questions

Try it free, in your browser, at your own pace.

Try it free