data reduction (calculating means)

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LisaSHC
Posts: 2
Joined: Tue Mar 10, 2009 6:18 pm

data reduction (calculating means)

Postby LisaSHC » Tue Mar 10, 2009 6:40 pm

I have data for 131 participants with 8 different variables.

Variables are:
Task Order (1 or 2)
Block# (1, 2, 3, and 4)
SubTrial (1 to 128 for each block)
Delay (varies in msec and is only relevant for Inb=1)
Inb (0 or 1)
Acc (1 or 0 with 1 being accurate and 0 being inaccurate)
RT (reaction time in milliseconds and varies)

Currently the data are structured like this:

Subject TaskOrder Block# SubTrial Delay Inb Acc RT
1 1 1 1 xms or 0 0 or 1 0 or 1 xms or 0
1 1 1 2 " " " "

The data continue in this fashion for 128 lines then switch to Block 2 SubTrial 1, etc. After 128 lines x 4 the data begin for Subject 1.

I want to calculate means for Delay and RT for Inb=0 and Acc=0, Inb=0 and Acc=1, Inb=0 and Acc =1, and Inb=1 and Acc=0 for each subject. I do not want means for each block but want to collapse across block. Please help!
statman
Administrator
Posts: 2700
Joined: Tue Jun 12, 2007 12:08 pm
Location: Florida, USA

Re: data reduction (calculating means)

Postby statman » Tue Mar 10, 2009 6:57 pm

So, if want stats by variable based on a 'filter' then look into the Select If or even set-up a new variable with the Recode
See the note below

NOTE: Please read the Posting Guidelines and always tell us your OS, the SPSS version and information about your study and data!

Statman
Statistical Services
Fierce
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Posts: 391
Joined: Sun Dec 28, 2008 5:55 pm
Location: Belo Horizonte, Brasil

Re: data reduction (calculating means)

Postby Fierce » Tue Mar 10, 2009 7:10 pm

You can get it using DATA>AGGREGATE if you want values to be in your dataset. Choose the ID, INB and ACC as break variables and the Delay and RT for summaries and choose MEAN as function (it is the default, I think). You'll have 2 new variables with means for each combination of the break variables.
BR

NOTE: "Please read the Posting Guidelines and always tell us your OS, the SPSS version and some information about your data!" - by statman.

Disponível em português (mas prefira inglês para que outros também entendam a solução).
LisaSHC
Posts: 2
Joined: Tue Mar 10, 2009 6:18 pm

Re: data reduction (calculating means)

Postby LisaSHC » Tue Mar 10, 2009 10:38 pm

Fierce,
That worked! Thank you so much. You have saved me a lot of time. :P

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