Record/log the order of trials within a loop
Hi there,
Sorry if this has been asked before or if its really obvious.
So I have a loop that contains three trials and will present these to participants in random order. Also, within each trial is another loop that show participants three trials in a random order. I.e. there are 3 blocks (presented in random order) of 3 trials (also presented in random order) meaning a total of 9 trials overall.
How would I go about logging/recording the order in which participants receive each of these trials(I want to check participants' judgements do not differ due to fatigue effect)? Is there a variable that I can use to log the presentation of these trials or to tell me whether a trial came first second or third? Or could I use some Python to count the order of presentation?
Thanks in advance,
Matthew
Comments
Hi Matthew,
You can add a variable to the loop table, that codes the trial type. That trial type would then essentially be the order, right? The same works for blocks.
Does that make sense or am I misunderstanding your problem?
Eduard
Hi Eduard,
Thanks for the response. Sorry my question was probably not well presented.
This is how my experiment is laid out so far:
Then in each 'story' the participant makes a single judgement which I record in a logger at the end of the experiment.
Basically, I would like my excel output at the end of the experiment to tell me which block type (i.e. sequences 1, 2 and 3) were presented first, second and third to the participant. And which story type within each sequence was presented first, second and third to participants
Does that make sense?
Matthew
Hi Matthew,
Then in each 'story' the participant makes a single judgement which I record in a logger at the end of the experiment.
I think the confusion is here. If you want to record a response to each trial that you have (or stories in your case), you need to add a logger to each trial, right after the response was given. If you add it only once in the end of the experiment, you would only log the very last response and nothing else. Have you checked out the beginner's tutorial? The procedure there is explains it quite nicely, I think. You can also check out this part of the docs.
I would like my excel output at the end of the experiment to tell me which block type (i.e. sequences 1, 2 and 3) were presented first, second and third to the participant.
The log file will contain one line for every response that you have. On that line, all the variables that are set will also be written. Therefore, if you are in a block, in which
sequence_nris set to 1, there will be a column with 1 in all trials of that block. So, essentially, the order of the blocks is coded in the order of the rows in your log file.Does that make more sense?
Eduard
Hi Eduard,
Thanks. So I have actually set my logger at the end of the experiment to record judgements made on all of the trials not just the last trial (it also records demographic info indicated at the start and counts memory checks).
The reason I had done this at the end of the experiment is because I remember reading somewhere that you should only use one logger otherwise the loggers get confused (I may have misinterpreted/misread this however!).
Currently, my log file/spreadsheet just gives the variables in alphabetical order
So, if I set a logger at the end of each trial as you suggest, the log file/spreadsheet will present the data in the order in which the participant received each of the trials?
Matthew
that you should only use one logger otherwise the loggers get confused
Almost true. You should use more than one unique logger, but if you use linked copies of the same logger, everything is good.
I also recommend that you start with logging all variables, only if you know exactly what you are doing and finished preparing your experiments, it makes sense to reduce the number of logged variables and cherrypick the important ones.
the log file/spreadsheet will present the data in the order in which the participant received each of the trials?
Exactly!
Ahh that makes sense. Great, thanks for your help, Eduard!