IDEAS home Printed from
   My bibliography  Save this article

Forgetting and the Learning Curve: A Laboratory Study


  • Charles D. Bailey

    (The Florida State University, College of Business, Tallahassee, Florida 32306-1042)


The industrial learning curve is widely used to predict costs and labor requirements wherever learning is taking place. Little is known, however, about the reverse of this process: the forgetting that occurs during production interruptions. The ability to estimate cost increases due to forgetting would be useful for economic lot size determinations, bidding on repeat orders, estimating the cost of strikes, and so on. Empirical studies apparently have not been published. Field data are difficult to obtain and easily confounded by extraneous variables. Thus a laboratory experiment was undertaken to test selected variables that should (or should not) affect forgetting. A review of relevant psychological literature reveals two key findings: (1) Forgetting may be negligible for "continuous control" tasks but considerable for "procedural" tasks. Bicycle riding is representative of continuous control, while operating a computer is clearly procedural. (2) Forgetting is a function of the amount learned and the passage of time, not of the learning rate or other variables. The experiment employed paid subjects who worked between four and eight hours to learn both a procedural task and a continuous control task (assembling and disassembling a mechanical apparatus). Each subject returned at an assigned time, up to 114 days later, and repeated the task for about four hours. Thirty-one of 35 subjects produced usable data. For purposes of the study, "forgetting" was defined as the excess of actual time over learning-curve-predicted time, summed over the first four trials after the interruption. "Amount learned" was defined as the achieved reduction in time-per-unit before interruption. As hypothesized, forgetting was a function of amount learned and elapsed time, with 71 percent of the variance being thereby explained in a regression equation. Forgetting rate does not appear to be related to learning rate, contrary to conventional wisdom in the learning curve literature. Additional findings are (1) that the relearning rate is not correlated with the learning rate, but may be related to skill factors and the degree of original learning; (2) that subjects have poor insight into their memory states; and (3) that, within the specific task, learning rate is highly correlated with the time taken to complete the first unit. Further research is indicated to investigate whether the forgetting rate may be constant, and therefore applicable across broad classifications of tasks. The determinants of relearning also are a suggested area of investigation. The results of this study apply to individual learning curves, and questions remain concerning the aggregation of individual performance into group performance.

Suggested Citation

  • Charles D. Bailey, 1989. "Forgetting and the Learning Curve: A Laboratory Study," Management Science, INFORMS, vol. 35(3), pages 340-352, March.
  • Handle: RePEc:inm:ormnsc:v:35:y:1989:i:3:p:340-352

    Download full text from publisher

    File URL:
    Download Restriction: no


    All material on this site has been provided by the respective publishers and authors. You can help correct errors and omissions. When requesting a correction, please mention this item's handle: RePEc:inm:ormnsc:v:35:y:1989:i:3:p:340-352. See general information about how to correct material in RePEc.

    For technical questions regarding this item, or to correct its authors, title, abstract, bibliographic or download information, contact: (Mirko Janc). General contact details of provider: .

    If you have authored this item and are not yet registered with RePEc, we encourage you to do it here. This allows to link your profile to this item. It also allows you to accept potential citations to this item that we are uncertain about.

    We have no references for this item. You can help adding them by using this form .

    If you know of missing items citing this one, you can help us creating those links by adding the relevant references in the same way as above, for each refering item. If you are a registered author of this item, you may also want to check the "citations" tab in your RePEc Author Service profile, as there may be some citations waiting for confirmation.

    Please note that corrections may take a couple of weeks to filter through the various RePEc services.

    IDEAS is a RePEc service hosted by the Research Division of the Federal Reserve Bank of St. Louis . RePEc uses bibliographic data supplied by the respective publishers.