Repeated Measures
Locked
 
|
Hi Guys: I'm really stumped trying to RUN a repeated -measures model in an experiment. Here's the descriptive:
Hamsters feeded on a daily basis for over a week.
4 different Rx, each one with 4 different concentration in mg.
N for each Rx/concentration = 4
Outcome: Change in Glucose Level
Here's the syntax:
GLM week_1 week2 week_3 week_4 week_5_ week6 week_7 week_8 week_9 week_10 BY Rx /WSFACTOR = week 10 Polynomial /METHOD = SSTYPE(3) /POSTHOC = Rx ( TUKEY BONFERRONI T2 ) /PLOT = PROFILE( Rx week*Rx ) /EMMEANS = TABLES(Rx) COMPARE ADJ(BONFERRONI) /PRINT = DESCRIPTIVE OPOWER HOMOGENEITY /CRITERIA = ALPHA(.05) /WSDESIGN = week /DESIGN = Rx . There's the problem: Output came empty, no univariate or multivariate results, no mauchly's test...
Any help would be appreciated!
-- |
|
|
Geronimo,
I don't understand your design. You say you '4 different Rx, each one with 4
different concentration in mg.' Do you mean
that the treatment consists of 4 difference concentrations of X? Or, do
you mean something else? You say 'Hamsters feeded (fed) on a daily basis
for over a week.' Your hamsters probably appreciated being fed on a daily basis!
Snarky comment aside, did you have one group of hamsters that received one
at a time all of the different concentrations of X or did you have four (or some
other number) groups of hamsters and each group received just one of the
concentrations of X? By the way, how many hamsters did you have in each group
and how many did you have in total?
Gene
Maguin
From: SPSSX(r) Discussion [mailto:[hidden email]] On Behalf Of Gerónimo Maldonado Sent: Monday, February 14, 2011 10:54 AM To: [hidden email] Subject: Repeated Measures Hi Guys: I'm really stumped trying to RUN a repeated -measures model in an
experiment. Here's the descriptive:
Hamsters feeded on a daily basis for over a week.
4 different Rx, each one with 4 different concentration in
mg.
N for each Rx/concentration = 4
Outcome: Change in Glucose Level
Here's the syntax:
GLM week_1 week2 week_3 week_4 week_5_ week6 week_7 week_8 week_9 week_10 BY Rx /WSFACTOR = week 10 Polynomial /METHOD = SSTYPE(3) /POSTHOC = Rx ( TUKEY BONFERRONI T2 ) /PLOT = PROFILE( Rx week*Rx ) /EMMEANS = TABLES(Rx) COMPARE ADJ(BONFERRONI) /PRINT = DESCRIPTIVE OPOWER HOMOGENEITY /CRITERIA = ALPHA(.05) /WSDESIGN = week /DESIGN = Rx . There's the problem: Output came empty, no univariate or
multivariate results, no mauchly's test...
Any help would be appreciated!
-- |
|
|
Hi Gene: Sorry for the orthographic monstrosity... yes my design consists in 4 treatments:
* X
* Y
* Z
* A
Each contains 4 concentration
* X (5mg)
* X (10mg)
* X (15mg)
* X(20mg)... and so forth with each one of the treatments.
The outcome of the experiment is know which Rx @ what concentration is better in reducing C6H12O6 in mice
Thanks for any input!
|
|
|
I've appended your first post below to point out why there is confusion
over your design. Let me make the following points: (1) You say you have 4 treatments and 4 concentrations which would suggest you have a 2-way completely within-subject design where every subject (hamster) is measured 16 times (i.e., 4 x 4 = 16 combinations or treatments and concentrations). So, there should 16 variables specified as containing the dep var (glucose level). So, we expect to Tx1Con1, Tx1Con2, Tx1Con3, Tx1Con4, Tx2Con1, ... Tx4Con4. This assuming that you used a full factorial design for the 4x4 within-subject factors. (2) In your syntax below you have "week" instead of treatment combination and "Rx" which is specified as a between-subjects factor. Did you have different groups of subjects/hamster receive different treatments or was there one group that received the 16 combination I specify in (1) above? What exactly is "week" supposed to represent? Why is there only 10 weeks? You don't even mention week in your follow-up post. More info is required. -Mike Palij New York University [hidden email] -------------------First Post-------------------- Hi Guys: I'm really stumped trying to RUN a repeated -measures model in an experiment. Here's the descriptive: Hamsters feeded on a daily basis for over a week. 4 different Rx, each one with 4 different concentration in mg. N for each Rx/concentration = 4 Outcome: Change in Glucose Level Here's the syntax: GLM week_1 week2 week_3 week_4 week_5_ week6 week_7 week_8 week_9 week_10 BY Rx /WSFACTOR = week 10 Polynomial /METHOD = SSTYPE(3) /POSTHOC = Rx ( TUKEY BONFERRONI T2 ) /PLOT = PROFILE( Rx week*Rx ) /EMMEANS = TABLES(Rx) COMPARE ADJ(BONFERRONI) /PRINT = DESCRIPTIVE OPOWER HOMOGENEITY /CRITERIA = ALPHA(.05) /WSDESIGN = week /DESIGN = Rx . There's the problem: Output came empty, no univariate or multivariate results, no mauchly's test... Any help would be appreciated! -- ----- Original Message ----- From: Gerónimo Maldonado To: [hidden email] Sent: Monday, February 14, 2011 6:29 PM Subject: Re: Repeated Measures Hi Gene: Sorry for the orthographic monstrosity... yes my design consists in 4 treatments: * X * Y * Z * A Each contains 4 concentration * X (5mg) * X (10mg) * X (15mg) * X(20mg)... and so forth with each one of the treatments. The outcome of the experiment is know which Rx @ what concentration is better in reducing C6H12O6 in mice Thanks for any input! ===================== 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 |
«
Return to SPSSX Discussion
|
1 view|%1 views
| Free forum by Nabble | Edit this page |