Old and New Stimuli

joelsolo99

Hi, first post here

I've tried using the search because I am sure this has been asked before but I cannot find any solution to my issue.

I am making a recognition experiment which involves showing participants stimuli in the loop (exposure phase) and then in the second loop (recognition phase) asking them if they have seen this before.

My experiment is structured so that all 240 stimuli are selected at random: 120 are shown in the first loop and then all 240 are shown in the second loop. The participant then has to rate how confident they are on a scale of 1-6 that they have seen the stimulus before. I am unsure how to determine in the program whether the stimulus was chosen in the first phase or not.

I have tried creating a list containing all the stimuli that have been shown by making an inline script which records the stimuli that were selected by the experiment, but have been unable to use this list to determine correctness in the second loop.

Any help would be greatly appreciated!

eduard

Hi,

Without getting into the structure of the experiment, a way to check accuracy could be following:

# first select the first half stimuli
import random
all_stim  = [1,2,3,4,5,6,7,8]
random.shuffle(all_stim)
first_round_stim = all_stim[:4]
# later during the second phase, check for every item whether it has been part of the first part:
for stim in all_stim:
    if stim in first_round_stim:
         old = 1
     else:
         old = 0

Does that help?