Four experiments examined the effects of increasing the number of food pellets given to
hungry rats for a lever‐press response. On a simple variable‐interval 60‐s schedule …

In Experiment 1 rats were trained to press a lever on a variable‐ratio schedule of food
presentation and were then exposed to progressively increasing magnitudes of food …

Three groups of rats pressed a lever for milk reinforcers on various simple reinforcement
schedules (one schedule per condition). In Group M, each pair of conditions included a …

Rats' lever pressing was studied on three schedules of reinforcement: fixed interval,
response‐initiated fixed interval, and fixed ratio. In testing, concentration of the milk …

On each of variable‐ratio 10, 40, and 80 schedules of reinforcement, when rats' lever‐
pressing rates were stable, the concentration of a liquid reinforcer was varied within …

Two differences between ratio and interval performance are well known:(a) Higher rates
occur on ratio schedules, and (b) ratio schedules are unable to maintain responding at low …

Two experiments investigated whether steady‐state interactions in multiple schedules
depend exclusively on the following schedule of reinforcement. Experiment 1 used a four …

Interval schedules of reinforcement maintained pigeons' key‐pecking in six experiments.
Each schedule was specified in terms of mean interval, which determined the maximum rate …

Two groups of albino rats differing in degree of food deprivation time were trained on a fixed-
interval reinforcement schedule in a Skinner box. Additional practice on this task revealed …

Four rats responded on one‐minute variable‐interval schedules with several variations in
peak‐force of response required for food reinforcement. Measures of peak force and rate …