For which of the following baseline graphs would it be most appropriate to introduce the independent variable for a behavior targeted for increase?

Raine, a BCBA, is running a study that teaches task engagement during circle time activities. She is using a concurrent multiple baseline design and starts the study with five participants. Raine systematically introduces a timer that goes off every 60 seconds. The timer is attached to each participant and is designed to prompt the child to do a self-check for task engagement during the intervention phase. Raine simultaneously collects data on eye contact and if the child’s body is facing the circle time leader. Halfway through Raine’s study, one of the participants moves to a different school and is unable to continue participating in the study. In this scenario, which of the following is most likely an example of attrition? 

When teaching his client new skills, Robbie, a BCBA, uses three mastered tasks between acquisition targets when teaching his client. After a couple trials, he then uses two mastered tasks between acquisition targets. Next, he only uses one mastered task between acquisition targets. Robbie is reducing the number of mastered tasks between acquisition targets to see if the rate of acquisition is the same or better with less mastered targets between acquisition tasks.  Which type of analysis is Robbie conducting?

Serge is interested in observing how often Camilla, one of his clients, raises her hand to participate during math class. Serge enters the classroom, takes out a pen and a piece of paper, and begins recording as soon as the math class starts. He marks each time Camilla raises her hand to participate. Serge ends his observation as soon as the math class ends. This is an example of a(n):

Raj is measuring how often his client can stay on task during a designated time. He breaks the designated time into 30-second intervals and reports the percentage of intervals for which his client stayed on task for the full 30 seconds. Which recording method did the Raj use?

Joe does one pull-up, and 45 seconds later, does another pull-up. This is an example of:

Carmella runs a pool hall and is interested in whether      her customers regularly use all 8 pool tables at the same time. Because she cannot continuously observe her customers at the tables throughout the day due to other duties, which recording method would be best for Carmella to use?

Brandon would like to increase the number of flashcards he      can correctly answer in a 1-minute interval. Which of the following continuous recording methods would be best for Brandon to use?

A running app on Jaymes’s phone sends a notification and, 3 seconds later, Jaymes begins to run and runs for 10 minutes. After running for 10 minutes, Jaymes stops running. After 2 minutes, the running app sends another notification, and Jaymes begins to run again. Jaymes runs 15 times. Each running session lasts 10 minutes. Which part of this scenario exemplifies the fundamental property of temporal extent?

Which of the following is an example of count?