Assent Data Collection Methods That Actually Work in Session

Assent data collection in ABA comes down to three working units: frequency, rate, and an initiation behavior the kid taps before a task starts. A BCBA is a board certified behavior analyst. If your supervisor just told you to add assent to the BIP (behavior intervention plan, the written plan that drives session) and you are staring at a blank data sheet, this page is for you. The tap the card method is the simplest version. You pick one card, place it on the table, and the client taps it to say I am ready. Every tap is one data point. Every refusal to tap is also one data point. That is it. No vague rating scale. No 1 to 5 affect score. Just a behavior you can count.

Pick one assent behavior, not five#

The biggest mistake in assent data is picking too many behaviors at once. New BCBAs read about assent withdrawal and want to track everything. Crying, pushing the table, eloping, head down, the no word, slow approach. By Wednesday the data sheet has five blank columns and the RBT (registered behavior technician, the person running the session) has filled in none of them. A blank data sheet teaches you nothing.

When it comes to tracking, right, when it comes to the nuts and bolts, I found that the best thing you can do is identify a singular assent provision behavior. And track that, right? Start with one behavior that you think is highly relevant, highly relevant that occurs right before perhaps the aversive task. From the talk — Matt Harrington

Pick one. The one that already shows up right before the hard task. Maybe it is the kid pushing the worksheet away. Maybe it is the kid getting up and walking to the couch. Whatever it is, that is your target. Track only that one for the first month. You can add a second behavior later, after the team is hitting IOA on the first. IOA is interagreement, which means two people watch the same session and mark the same behavior the same way.

Frequency and rate: the simplest data sheet#

Once you have your one behavior, the data sheet is a column with tally marks. Every time the behavior happens, the RBT puts a tick. Every time the kid does the assent provision version, like tapping the card, the RBT puts a tick in the other column. At the end of session you have two numbers: how many times the kid gave assent, and how many times the kid pulled it.

So now we have assent provision tracking. We have assent withdrawal. So, what do we do with this information? So, now we're tracking it. Maybe we're doing frequency of assent provision, frequency of assent withdrawal. We turned into a rate. From the talk — Matt Harrington

Rate is just frequency divided by time. If the session was 90 minutes and you saw four assent withdrawals, that is 0.044 per minute. Track rate, not just raw count, because session length changes. A 30 minute session with three refusals is much worse than a 90 minute session with three refusals. Rate makes the data honest across sessions.

When the client has no clear assent behavior: teach an initiation behavior#

Most clients do not have a clean assent behavior that already happens. They have a fuzzy version. They look at the BT. They sigh. They sit down. None of those are easy to count. So you build one.

Well, what I've seen in the past and what I've done really that's worked fairly well myself is an initiation behavior. It's a behavior that begins a chain that includes the task demand. The client then engaged in that initiation behavior of tapping the picture card. And that communicates to the technician that the client is now ready to work. From the talk — Matt Harrington

The setup is simple. Print a picture card. Could be a thumbs up, could be a green dot, could be the work word. Place it on the table before the task. The BT says, when you are ready, tap the card. The kid taps. Task starts. Now you have a clean assent point. If the kid does not tap within ten seconds, that is assent withdrawal. Both are countable. Both go on the data sheet.

The reason this works is it gives the kid a way to say yes that does not require words. It also gives the BT a way to count something that used to be a vibe.

Momentary time sampling for assent withdrawal in a hangout zone#

Frequency works when the behavior has a clean start and stop. Some assent behaviors do not. If the kid is just hanging out in the NCR (noncontingent reinforcement, the part of session where the kid gets free access to fun stuff without having to earn it) corner with the iPad, you are not counting refusals. You are checking in on engagement. For that, you use interval recording.

It's also worthwhile to consider momentary time sampling or whole time sampling or partial interval sampling. It's worthwhile to maybe start a 10-minute timer and track how often the client is engaging in the hangout context where it's maybe their NCR zone where they have functional reinforcers. From the talk — Matt Harrington

Momentary time sampling means you set a timer for short blocks. Every 60 seconds, the BT looks up. If the kid is engaged in the moment the timer beeps, that is a yes. If not, that is a no. At the end of ten minutes you have ten data points. Six yeses out of ten is 60% engagement. That is a number you can graph and trend.

Use this method when assent looks like staying in the room, staying in the chair, or staying with the toy. Use frequency when assent looks like tapping the card or pushing the worksheet away.

What to write on the actual data sheet (with a real example)#

Here is a basic sheet for a 60 minute session, kid named B, target is math worksheet trials.

Column 1: date. Column 2: BT initials. Column 3: session length in minutes. Column 4: tally of assent provisions (taps of the card). Column 5: tally of assent withdrawals (no tap within 10 seconds, or stops mid-trial). Column 6: rate per minute for each.

A real row: 2026 06 12, BT JR, 60 min, taps 14, withdrawals 3, rate 0.23 taps per minute, rate 0.05 withdrawals per minute. That is a clean session. The kid said yes 14 times and no 3 times. You can graph rate over the week and watch it shift as the program changes.

If you want one extra column, add a notes column for what was happening when the withdrawal hit. Was it the third demand in a row? Was it after a non-preferred subject? That context is what lets you change the program next week.

Three common mistakes that ruin assent data#

First mistake: tracking too many behaviors. You already heard this one. Pick one. Add later.

Second mistake: not training the BT on what counts. If two BTs run the same kid and one counts a head down as withdrawal and the other does not, your data is junk. Do a 15 minute IOA pass with each BT in the first week. Watch the same session. Compare tallies. If you are below 80% agreement, the definition is too loose. Tighten it. The fix is almost always making the behavior more specific. Not just no, but no after a task demand within 10 seconds.

Third mistake: only collecting data on the hard sessions. If the BT only marks the sheet when the kid melts down, you do not know what good looks like. You only see bad days. Set the sheet up so it gets filled every session, even the boring quiet ones. The boring days are your baseline.

How long to baseline before you trust the data#

Five sessions is the floor. Most cases I have run, you want about a week to ten days of consistent data before you draw any conclusions. The first three sessions are usually noise. The kid is figuring out the new card. The BT is figuring out the definition. Sessions four through seven are when the real pattern shows up.

Graph rate per session on a simple line. If you see a stable level over five points, that is your baseline. Now you can start changing something in the program and watch the rate move. If you change three things at once you will never know which one mattered. Change one thing per week.

If the rate of withdrawal is dropping and the rate of provision is rising, the program is working. If both are flat, something is off. If both are climbing, the kid is more engaged overall, which usually means you have a better assent setup but also more chances to refuse. That is normal. Look at the ratio, not the raw counts.

Frequently asked questions#

Can RBTs collect assent data, or does it have to be the BCBA?

RBTs collect almost all session data. Assent data is no different. The BCBA writes the operational definition, trains the RBT on it, and checks IOA in the first week or two. After that the RBT runs the sheet. The BCBA reviews the data weekly. The only piece that has to stay with the BCBA is the program change decision. The RBT does not modify the plan based on the trend. That is on you.

Is event recording or interval recording better for assent?

Event recording, which is the same as frequency, is better when the behavior has a clean start. Tap the card. Push the worksheet. Each one is countable. Interval recording is better when the behavior is more about being in or out of an engagement state. Hanging out in the NCR zone. Staying in the work chair. Use whichever matches what the assent looks like for that kid. You can use both in the same session if you want one number for taps and one number for engagement.

Do I need IRB approval to start collecting assent data in a clinical setting?

No. IRB review is for research. Clinical data collection on a client you serve, even on assent, is part of clinical practice. You do need a clear note in the treatment plan that says you are tracking assent, what behaviors count, and how you are using the data. That is documentation, not research approval. If you plan to publish the data later, that is when you talk to your supervisor about IRB.

Watch the full talk#

If your team is about to roll out assent tracking on a case, the full one-hour CEU walks through the data sheet design, the initiation behavior setup, and how to handle the first month of messy data. It is free and counts for one general learning credit.

Watch the full CEU on assent and taking data