School of Psychology, University of Waikato, Hamilton, New Zealand.
J Exp Anal Behav. 2011 May;95(3):289-304. doi: 10.1901/jeab.2011.95-289.
In comparing open and closed economies, researchers often arrange shorter sessions under the former condition than under the latter. Several studies indicate that session length per se can affect performance and there are some data that indicate that this variable can influence demand functions. To provide further data, the present study exposed domestic hens to series of increasing fixed-ratio schedules with the length of the open-economy sessions varied over 10, 40, 60, and 120 min. Session time affected the total-session response rates and pause lengths. The shortest session gave the greatest response rates and shortest pauses and the longest gave the lowest response rates and longest pauses. The total-session demand functions also changed with session length: The shortest session gave steeper initial slopes (i.e., the functions were more elastic at small ratios) and smaller rates of change of elasticity than the longest session. Response rates, pauses, and demand functions were, however, similar for equivalent periods of responding taken from within sessions of different overall lengths (e.g., total-session data for 10-min sessions and the data for the first 10 min of 120-min sessions). These findings suggest that differences in session length can confound the results of studies comparing open and closed economies when those economies are arranged in sessions that differ substantially in length, hence data for equivalent-length periods of responding, rather than total-session data, should be of primary interest under these conditions.
在比较开放经济和封闭经济时，研究人员通常会在前者的条件下安排比后者更短的实验时段。多项研究表明，实验时段的长短本身会影响表现，并且有一些数据表明，这个变量会影响需求函数。为了提供更多的数据，本研究让家鸡接受一系列递增的固定比率方案，其中开放经济时段的长度在 10、40、60 和 120 分钟之间变化。时段时间影响总时段反应率和停顿时间。最短的时段产生最大的反应率和最短的停顿时间，最长的时段产生最低的反应率和最长的停顿时间。总时段需求函数也随时段长度而变化：最短的时段具有更陡的初始斜率（即，在小比例下函数更具弹性），而最长的时段则具有较小的弹性变化率。然而，对于来自不同总长度时段内的等效响应时段（例如，10 分钟时段的总时段数据和 120 分钟时段的前 10 分钟数据），反应率、停顿时间和需求函数是相似的。这些发现表明，当开放经济和封闭经济的实验时段长度差异很大时，时段长度的差异可能会混淆比较这两种经济的研究结果，因此在这些条件下，应主要关注等效反应时段的数据，而不是总时段数据。
