Time-based and count-based measurement of preference.
Time and count give the same matching-law picture, so track whichever is easier.
01Research in Context
What this study did
Researchers compared two ways to track choice. They recorded how often a lever was pressed and how long it stayed pressed. Both measures were taken while reinforcement rates changed.
The goal was to see if simple counts and time-based data tell the same story.
What they found
Time and count moved together almost perfectly. When one went up, the other did too. Both followed the matching law, so either measure could be used.
How this fits with other research
Rilling et al. (1969) first showed pigeons’ time allocation matched reinforcement ratios. The 1976 study built on that by proving the same rule works for counts and time in lever pressing.
Herrnstein et al. (1979) later split response allocation into ‘propensity’ (time) and ‘speed’ (rate). They found time allocation was the steadier measure, echoing the 1976 finding that time data are reliable.
Byrne et al. (2019) extended the idea to response duration. They showed duration tracks contingencies as well as counts do, confirming that time-based dimensions remain useful decades later.
Why it matters
You can save effort by choosing the easier measure. If counting presses is simple, use that. If timing is simpler, use a stopwatch. Either way, the matching law still guides your interpretation. Pick the data stream that fits your setting and move on.
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Join Free →During the next free-operant preference assessment, time one option with a stopwatch and count the other with a clicker; plot both to confirm they line up.
02At a glance
03Original abstract
Rats' pressing on two levers was reinforced according to two independent variable-interval schedules that were varied during the experiment. Since the levers were connected directly to the programming equipment, bypassing the standard pulseformers, reinforcement could occur while a lever was held down. Although the time a lever was pressed might, therefore, have varied independently of number of presses, these two measures covaried substantially, because the average duration of the presses remained roughly constant. This rough invariance may have resulted from the rats' tendency to make bursts of brief presses (i.e., to jiggle the levers), even though the contingencies encouraged holding. When duration did vary, presses on the two levers tended to vary together. As a result, relative time spent pressing corresponded closely to relative number of presses. Both of these measures conformed well to the matching law. Absolute behavioral frequency at a lever, measured either way, varied directly with proportion of reinforcement for that lever, in accordance with the generalized version of the matching law. Number of presses seemed, on balance, to be a slightly more reliable measure than pressing time. The substantial interchangeability may prove more significant than the slight disparity, however, because it supports the notion that all behavior can be measured on a common scale of time.
Journal of the experimental analysis of behavior, 1976 · doi:10.1901/jeab.1976.26-27