Constituents of response rates.
Measure time in the activity first; speed is a shaky signal.
01Research in Context
What this study did
The researchers asked a simple question: when reinforcement schedules change, what part of behavior stays steady?
They watched how much time animals spent on a lever and how fast they pressed during that time.
By shifting reinforcement rates, they could see which measure wobbled and which held firm.
What they found
Time on the lever stayed locked to the new reinforcement rate.
Momentary pressing speed jumped around and often missed the change.
The team called the steady time measure "propensity" and said it is the cleaner yard-stick.
How this fits with other research
Rilling et al. (1969) showed pigeons divide their minutes between keys exactly like the payoff ratio.
The 1979 paper keeps that idea but warns speed counts can hide the pattern.
Baum (1976) found time and count usually match, yet the new data say time is the safer pick when schedules shift.
LeBlanc et al. (2003) later proved rich schedules also protect accuracy from disruption, backing the view that molar measures behave more reliably.
Why it matters
When you graph a client’s behavior, track how long they stay in the task, not just how many responses they cram into a minute.
If you use speed alone you might chase noise and miss the real effect of your reinforcement plan.
Want CEUs on This Topic?
The ABA Clubhouse has 60+ free CEUs — live every Wednesday. Ethics, supervision & clinical topics.
Join Free →Start a timer when the client enters the work area and log total seconds engaged before you count individual responses.
02At a glance
03Original abstract
Response rate and the proportion of time pigeons allocated to a key-pecking activity were measured on several basic types of reinforcement schedules. Reinforcement frequency was varied within each type of basic schedule, and the effects on two constituents of response rate were noted. Propensity, the proportion of time the birds spent on a platform in front of the key, showed very consistent effects as reinforcement frequency varied: in general, it decreased when reinforcement frequency markedly decreased and it increased when reinforcement frequency increased. Speed, key pecks per unit of time spent on the platform, showed inconsistent effects when reinforcement frequency varied. Consequently, response rate showed less consistent effects than did propensity. Cumulative response records demonstrated the existence of several different types of transitions or boundary states between the key-pecking activity and other activities. The types of transitions that occurred between activities depended on both the type of reinforcement schedule and the frequency of reinforcement. The propensity data support the position that general laws of behavior can be based on temporal measures of behavior. The speed data suggest that, if a complete assessment of the dynamic properties of behavior is to be achieved, measures of behavior must incorporate the structural variations in the operant unit.
Journal of the experimental analysis of behavior, 1979 · doi:10.1901/jeab.1979.32-341