Dear OpenSesame community
I’m currently working on a delay discounting task and I want to integrate an inline script which calculates an indifference point. Richards, Zhang, Mitchell and de Wit (1999) programmed a random adjusting-amount procedure to use the answers to previous questions to narrow the range of values from which the value for the next question was selected. I think it is a great way to determine the indifference point but it seems quite complicated (if someone has used this procedure on OpenSesame I would be very thankful for him/her to send me the script ). Right now I’m settling for an easier procedure by Du, Green, and Myerson (2002). The variable amount starts with half of the amount of the standard amount (say the standard amount is 100$ then the variable amount is 50$). If the participant chooses the standard amount the variable amount increases on the next trial by ¼ of the standard amount (in this case 50 + 25 = 75$). If the participant settles for the 75$ in the next round than the amount decreases by 1/8 of the standard amount (in this case 12.50$) and so on. This graphic by Frye, Galizio, Friedel, DeHart and Odum (2016) is very helpful to understand the principle:
I would like to integrate this procedure but I’m having trouble to do so. Could you please tell me how to create a code for the random adjusting-amount procedure?
Thank you so much in advance for your help!
If you need further information, please let me know!