McSweeney F K
J Exp Anal Behav. 1974 Mar;21(2):357-9. doi: 10.1901/jeab.1974.21-357.
Five pigeons pecked for food reinforcers on a concurrent variable-interval one-minute, variable-interval four-minute schedule. Each bird's body weight was varied from 80% of its free-feeding weight to 95% and then by 5% steps to 110% or until weight gains ceased. The coefficient of variation, but not the standard deviation, of the daily rate of responding on each of the component schedules increased with increases in body weight.
五只鸽子在同时呈现的一分钟可变间隔、四分钟可变间隔的食物强化程序下啄食。每只鸽子的体重从其自由进食体重的80%变化到95%，然后以5%的步长变化到110%，或者直到体重不再增加。随着体重增加，每个成分程序上每日反应率的变异系数（而非标准差）增加。
