Millisecond Forums

Stimulus-bound variables for trial blocks?

https://forums.millisecond.com/Topic17172.aspx

By SmaugWithACamera - 9/21/2015

Hello,

I have a problem with respect to coding my variables.
My experiment is a normal picture recognition experiment (learning phase ->distractor -> recognition phase) but when it comes to the recognition trials problems emerge:

The recognition trial blocks consists of a picture -> a yes/no decision (“Haveyou seen this item before?”) -> a confidence check (“On a scale of 1-6 decide how confident you are in your decision”).
(My alternative is to include the yes/no decision in the step with the picture displayed; for example by mouseclick.)

As there will be 100 pictures in the recognition phase there will be 100 recognition trial blocks per person. The purpose of the experiment is to determine the recognition rate for each individual picture.

Now the problem is that the data output for each trial ends up looking like this:

https://www.millisecond.com/forums/uploads/images/40a3cbcc-7208-43d1-b9eb-e2bb.png

(The data is from another experiment with a different question at stage two but the structure is the same.)

Basically this means that each answer and confidence check is just coded with generic markers such as “dummy”, “Text”/”Sicherheit” etc. and I can’t group them together for each picture. As a consequence I can’t examine the answers for the individual items.

Is it possible to solve this? For example I thought about coding an extra variable that automatically generates which picture the whole trial belongs to:

https://www.millisecond.com/forums/uploads/images/b9994acf-169b-4023-b488-1e20.png

(The variable column was added manually for this example to illustrate my idea of course.)

Can this be done? Or is there any alternative way to getaround this?

Best regards

Smaug

 
By Dave - 9/21/2015

You already have the answer in your script. Look at how values.datei is used throughout. Then either (1) *don't* set it to the value "dummy" in the "text" and "sicherheit" <trial>s or (2) create a new separate <values> entry that's only updated in the "objekt" <trial>s and log it to the data file.
By SmaugWithACamera - 9/22/2015

Hey Dave,

you're right. I didn't see the wood for the trees here.....I could fix it by now. Thank you!