For instructors

Using Leverlore in your course

Leverlore is a free, browser-based operant chamber for courses in learning, behavior analysis and the experimental analysis of behavior. Students need a link and nothing else: no accounts, no installs, no license keys.

What students can do

• Run a simulated rat on CRF, FR, VR, FI and VI schedules and watch a live cumulative record, with response-rate bins and an averaged FI curve.
• Put responding on extinction, then come back after a set number of days off to look for spontaneous recovery.
• Train a light or tone discrimination, run a generalization test, and read the gradient and discrimination index.
• Give the rat two levers on concurrent schedules, with a changeover delay, and fit the generalized matching law to their own data.
• Shape lever pressing by hand with a clicker, and change hunger, reinforcer size and quality, delay and lever effort.
• Practice reading records with generated quizzes, mystery schedules, design challenges and a timed exam.

Four guided labs, ready to assign

Each guided lab has goals, numbered steps with one-click setup buttons, and reflection questions you can use as a write-up prompt: ratio schedules (FR vs VR), interval schedules (FI vs VI), extinction and spontaneous recovery, and discrimination and stimulus control. Students can export the session event log as CSV and the graphs as PNG and attach both to a lab report.

Setup links

Settings can be passed in the address, so you can post a link that opens the lab ready for an exercise. Adding a seed makes the simulated rat behave the same way for everyone who opens that link, which helps when the class compares answers.

• FR 40 with a fixed seed, so every student sees the same rat /?schedule=FR40&seed=101
• FI 60 s with the FI average graph open /?schedule=FI60&tab=fi&seed=101
• Two levers on concurrent VI 15 s and VI 60 s, matching plot open /?conc=VI15,VI60&cod=2
• Hand-shaping with the clicker panel open /?manual=1
• Practice: name the mystery schedule /?view=practice&practice=mystery
• Practice: the ten-question timed exam /?view=practice&practice=exam

Other parameters: schedule (CRF, FRn, VRn, FIn, VIn), warp (fast-forward n simulated minutes), tab (cum, rate, fi, gen, match), preset and weight for rat variables.

Privacy

The lab has no sign-in and no analytics. A student’s rat, settings and practice scores are saved in their own browser (local storage) and are not uploaded anywhere, so there is nothing for you or anyone else to collect. Ask students to hand in the exported files instead.

How the rat behaves, and the limits

Responding is generated from published quantitative models of operant behavior, including bout-and-pause analyses of rat lever pressing, mathematical principles of reinforcement and the generalized matching law, tuned against rat data where it exists. The output is a teaching simulation, not real animal data, and some parameters are design choices rather than published constants. Classic textbook claims are sometimes refined: for example, the extinction burst appears in some sessions and not others, as it does in the research literature.

Alignment with the BCBA Test Content Outline

Guided labs and practice items are tagged with content areas from the BCBA Test Content Outline (6th ed.), such as B.9 simple schedules, B.11 extinction, B.13 stimulus discrimination, B.23 the matching law and C.10 cumulative records. The tags show alignment for study purposes only. Not affiliated with or endorsed by the BACB.

Questions are answered in the FAQ. For a quick primer to share with students, see schedules of reinforcement on a cumulative record.