Are my groups results from start to end statistically different from each other?

  Fozywoo 11:09 AM 03 Jun 12
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How shall I do an anova? Without splitting the groups so I have 2 groups- this brings up an error. I can do a general linear model but how do I analyse this please? It brings up two rows? See below:

'...Table 2 shows that waist measurement reductions were observed in both conditions. In inches, the waist measurement reduction was greater for the control group than the treatment group, with a mean of -1.65 inches (SD= 2.27) and -0.71 inches (SD= 1.24) respectively by the end of the 12 week study. A higher percentage loss was also identified in the control with a mean of -4.36% (SD= 5.82), compared to -1.81% (SD= 3.2) for the treatment.'

I am now looking at the significance of the waist changes between the placebo and active groups:

An anova brings up the message:

Warnings

Post hoc tests are not performed for Start Waist because there are fewer than three groups.

Post hoc tests are not performed for End Waist because there are fewer than three groups.

But I still get other parts of the test on output- is this ok not to have post hoc tests??

Heres my output for General Linear model. Can you tell me if this is significant please? I am looking at the significance of the waist changes between the placebo and active groups: Multivariate Tests(b) Effect Value F Hypothesis df Error df Sig. Partial Eta Squared timeofMeasurement Pillai's Trace .986 1054.832a 1.000 15.000 .000 .986 Wilks' Lambda .014 1054.832a 1.000 15.000 .000 .986 Hotelling's Trace 70.322 1054.832a 1.000 15.000 .000 .986 Roy's Largest Root 70.322 1054.832a 1.000 15.000 .000 .986 timeofMeasurement * Batch Pillai's Trace .006 .083a 1.000 15.000 .777 .006 Wilks' Lambda .994 .083a 1.000 15.000 .777 .006 Hotelling's Trace .006 .083a 1.000 15.000 .777 .006 Roy's Largest Root .006 .083a 1.000 15.000 .777 .006 a. Exact statistic b. Design: Intercept + Batch Within Subjects Design: timeofMeasurement

How do I know if they are statistically different from each other?

Thanks, Lauren.

  Forum Editor 11:42 AM 03 Jun 12

Are you using StatPlus 2007?

Click here for help

  Fozywoo 11:47 AM 03 Jun 12

I am using SPSS.

  Fozywoo 12:13 PM 03 Jun 12

Please can you help me?

  Forum Editor 12:18 PM 03 Jun 12

For SPSS help

try this

Or this

  wmary10 05:44 AM 04 Jun 12

please can you let us know the full meaning of SPSS.May be it's similar with the one I know.

  Fozywoo 10:49 AM 04 Jun 12

Statistical Package for the Social Sciences.

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