Posted by
Justin Blehar on
Sep 30, 2012; 2:55am
URL: http://spssx-discussion.165.s1.nabble.com/Controlling-for-Race-with-SPSS-20-tp5715386p5715391.html
Mike and Bruce,
Thanks so much for your input and it is helpful. I know power is an issue and collapsing the groups is a possibility but I'm concerned that I'd be missing something based on the descriptive stats I've already run (e.g. there is a large mean difference between the current smoker Caucasian group and working memory vs the current smoker African American group and working memory). The other option would be to just run the Caucasian sample. You've both given me some more to think about.
Thanks so much!
V/R
Justin
________________________________________
From: SPSSX(r) Discussion [
[hidden email]] on behalf of Bruce Weaver [
[hidden email]]
Sent: Saturday, September 29, 2012 11:10 PM
To:
[hidden email]
Subject: Re: Controlling for Race with SPSS 20
Given the sample sizes, I would forget about the distinctions between
Never-Former and Light-Heavy. That reduces it to a 2x2 (Smoker x Race) with
decent numbers in every cell.
Nonsmokers: Caucasian N = 44 African American N = 25
Current Smokers: Caucasian N = 32 African American N = 19
HTH.
Mike Palij wrote
> The simple answer to your question is that you use race as a
> grouping variable and you test for the whether the effect is the
> same across levels of race, that is, a nonsignificant two-way
> interaction -- assuming you have sufficient statistical power to
> detect such an interaction. If you have a significant two-way
> interaction, that is, effects are different for the two groups,
> then you can not come up with a result that applies
> to all persons independent of race -- the effect is dependent
> upon the race of the person. If the effect is nonsignificant
> with adequate power, then the effect holds for the races
> represented in the design.
>
> Given the sample sizes you list below, I think descriptive
> analyses are more appropriate than inferential analyses but
> what the hell, who knows, maybe N=2 does provide sufficient
> information for statistical testing. Knock yourself out.
>
> -Mike Palij
> New York University
> mp26@
>
>
> On Sat, Sep 29, 2012 at 8:32 PM, Justin Blehar <
> jnblehar@
> > wrote:
>> The population is outpatient individuals suffering from schizophrenia.
>> Most of the research I found either does not list race or only has
>> Caucasians in their sample. I have a large enough N to run only
>> Caucasians but this limits how well the results can be generalized. I'm
>> trying to avoid this if possible.
>>
>> Total Sample
>> Caucasian - N = 76
>> African American- N = 44
>>
>> Groups
>> Never Smokers: Caucasian N = 15 African American N = 23
>> Former Smokers: Caucasian N = 29 African American N = 2
>> Nonsmokers: Caucasian N = 44 African American N = 25
>> Heavy Smokers: Caucasian N = 9 African American N = 5
>> Light Smokers: Caucasian N = 23 African American N =14
>> Current Smokers: Caucasian N = 32 African American N = 19
>>
>> Thanks for your reply :)
>>
>> V/R
>> Justin
>> ________________________________________
>> From: SPSSX(r) Discussion [
> SPSSX-L@.UGA
> ] on behalf of Michael Palij [
> mp26@
> ]
>> Sent: Saturday, September 29, 2012 8:11 PM
>> To:
> SPSSX-L@.UGA
>> Subject: Re: Controlling for Race with SPSS 20
>>
>> If you control for race in whatever manner, to what population
>> would your conclusions apply to? And by population I mean
>> humans, not a mathematical distribution.
>>
>> -Mike Palij
>> New York University
>>
> mp26@
>>
>>
>> On Sat, Sep 29, 2012 at 6:18 PM, Justin Blehar <
> jnblehar@
> > wrote:
>>> Hello All,
>>>
>>> Not sure how much detail is needed so I'll give you a quick overall but
>>> I'm
>>> trying to control for race and am unsure how to best go about this. I
>>> know
>>> that I can run a partial correlation and control for race using the menu
>>> but
>>> is this really controlling for race? If not is there a better way? How
>>> would
>>> I do this for a t-test?
>>>
>>> This is a cross sectional design looking at cognition and smoking in a
>>> psychiatric population. There are six groups I'm looking at; Never
>>> Smokers,
>>> Former Smokers, Nonsmokers (includes both never smokers and former
>>> smokers),
>>> Heavy Smokers, Light Smokers, and Smokers (includes heavy and light
>>> smokers). I have 36 scale variables that I want to compare between each
>>> of
>>> these groups. When I break out the groups by race (just looking at box
>>> plots
>>> and mean comparisons) there are clearly some large race effects (e.g.
>>> parental education, level of functioning, IQ, etc...). I'd like to be
>>> able
>>> to correct for this in each analysis. I'm running both correlations and
>>> t-tests (maybe this isn't the best process?).
>>>
>>> If I run a partial correlation and control for race is this really
>>> controlling for race?
>>>
>>> When running the t-tests how do I control for race?
>>>
>>> Any help would be greatly appreciated.
>>>
>>> V/R
>>>
>>> Justin
>>
>> =====================
>> To manage your subscription to SPSSX-L, send a message to
>>
> LISTSERV@.UGA
> (not to SPSSX-L), with no body text except the
>> command. To leave the list, send the command
>> SIGNOFF SPSSX-L
>> For a list of commands to manage subscriptions, send the command
>> INFO REFCARD
>>
>> =====================
>> To manage your subscription to SPSSX-L, send a message to
>>
> LISTSERV@.UGA
> (not to SPSSX-L), with no body text except the
>> command. To leave the list, send the command
>> SIGNOFF SPSSX-L
>> For a list of commands to manage subscriptions, send the command
>> INFO REFCARD
>
> =====================
> To manage your subscription to SPSSX-L, send a message to
> LISTSERV@.UGA
> (not to SPSSX-L), with no body text except the
> command. To leave the list, send the command
> SIGNOFF SPSSX-L
> For a list of commands to manage subscriptions, send the command
> INFO REFCARD
-----
--
Bruce Weaver
[hidden email]
http://sites.google.com/a/lakeheadu.ca/bweaver/"When all else fails, RTFM."
NOTE: My Hotmail account is not monitored regularly.
To send me an e-mail, please use the address shown above.
--
View this message in context:
http://spssx-discussion.1045642.n5.nabble.com/Controlling-for-Race-with-SPSS-20-tp5715386p5715390.htmlSent from the SPSSX Discussion mailing list archive at Nabble.com.
=====================
To manage your subscription to SPSSX-L, send a message to
[hidden email] (not to SPSSX-L), with no body text except the
command. To leave the list, send the command
SIGNOFF SPSSX-L
For a list of commands to manage subscriptions, send the command
INFO REFCARD
=====================
To manage your subscription to SPSSX-L, send a message to
[hidden email] (not to SPSSX-L), with no body text except the
command. To leave the list, send the command
SIGNOFF SPSSX-L
For a list of commands to manage subscriptions, send the command
INFO REFCARD