Participant Everywhere vs Group Everywhere?

[EPL]

Hello, 

I am creating a study that requires participants (4 players) to make a series of choices (task 1), then randomly matches participants and asks them to guess what choices their partner made in the previous task (task 2), I then pay them based on the accuracy of their guesses. I am confused about how to do this. Do I need to make four versions of task 1 (one for each player), so that I refer back to each separately? Or, can I simply have the program "Compare Player B's task 2 response to player A's task 1 response" ? 

I guess this question boils down to the variable name/ variable context. If I specify something as "participant everywhere" does that mean that I can access it for each type of player separately? 

Thanks!

[Philipp Mamat]

Hello,

First some information about the contexts: You are able to access every variable of every context from everywhere in the experiment. SoPHIE's variable contexts are "only" made to keep a neat and tidy order.

For example each participant should have a payoff variable in which to save how much money (s)he gets from the study. If SoPHIE would not support variable contexts, you would need variables "payoffParticipant1", "payoffParticipant2" etc. By using PE (Participant Everywhere) variables, you only need to have a variable "payoff" which can have different values for different participants, by giving the participant's label in the variable API, you can access other participant's payoff variables. Next to this "participant" context, the second dimension in the variable context is the "process" context. This can be used e.g. to store the several choices of a participant in several rounds of the same setup. The (PSL / participant stepgroup loop) variable will can be called "choice" and accessed by giving the participant label, stepgroup label and stepgroup loop.

Please have a look at the API documentation: http://www.sophie.uni-osnabrueck.de/docs/apis/latest/sophie_variable_1_0_0.html and the wiki: http://www.sophie.uni-osnabrueck.de/wiki/pmwiki.php?n=SoPHIE.Variables
Here you will get an overview of all possible methods of the variable api with all parameters and default values. If you don't give all the parameters, SoPHIE will "magically" use the current participant / group / stepgroup / stepgroup loop.

Back to your question at hand:
You need only one step to make the choice (task 1) and a second step to guess the other participant's value (task 2). Possibly it makes sense to add some sync steps to make sure that all participants have completed task 1 when continuing with task 2.

Both tasks are independent, but the result page is not. Here you can retrieve any variables of any participants and compare them with each other.

I would suggest that you create two participant types (A and B) and a group structure so that each group has one "A" and one "B". When creating a session type you would create a session type with two groups, so you will have four participants. Then you can prepare the matching of who will interact with whom. By having only two participants in each group you can simply use the special label '%partner%' (http://www.sophie.uni-osnabrueck.de/wiki/pmwiki.php?n=SoPHIE.API#Special_Labels) to retrieve the partner's input value. The drawback is that in this (simple) design, the participants will always guess their partner's choice (A guesses B and vice versa). But I think it is best to live with this disadvantage at the beginning. After you are firm with this, you can go to the next level and implement a more complex matching and design in which there are no self-assessing pairs.

Hope this helps!
Regards,
 Philipp

-- 
Philipp Mamat
Symbic GmbH

Persönlicher Kontakt
Telefon: +49 (0) 541 / 50 79 97-18 | Telefax: -19
Mobil: +49 (0) 176 / 800 144 65 | Mail: philip...@symbic.de
___________________________________________________________
Symbic GmbH | www.symbic.de
Im ICO | Albert-Einstein-Str. 1 | DE-49076 Osnabrück 
Sitz der Gesellschaft: Marktstr. 14 | DE-38315 Hornburg

USt.-IdNr.: DE269573411
Eingetragen im Amtsgericht Braunschweig: HRB 202239
Geschäftsführer: Achim Hendriks, Philipp Mamat

--
You received this message because you are subscribed to the Google Groups "SoPHIE Community" group.
To unsubscribe from this group and stop receiving emails from it, send an email to sophie-communi...@googlegroups.com.
To post to this group, send email to sophie-c...@googlegroups.com.
Visit this group at http://groups.google.com/group/sophie-community.
To view this discussion on the web visit https://groups.google.com/d/msgid/sophie-community/5767cd8d-c787-4fbb-bff8-a886b1d4c775%40googlegroups.com.
For more options, visit https://groups.google.com/d/optout.