how to compute this?

[Wang Xu-4]

Hi all list members,
   I am a green hand at data analysis. Recently I was bumped by a scenario
presented in a paper by Roger Kirk
Kirk, R. E. (1996). Practical Significance: A Concept Whose Time Has Come.
Educational and Psychological Measurement, 56(5), 746-759.
on the page 755 of the paper the 2nd paragraph there is it. The summary of
the scenario is as follows,
13 patients were assigned evenly to control and experimental groups.t(10)
=1.61, p=.14, the mean for experimetal group is 13 IQ points higher than
that of control group. At the end of the paragraph the author said that a
95% confidence interval for the population mean difference is likely to be
between -6.3 and 32.3 IQ points. Do all the present conditions necessiate
the computation of confidence interval for the population mean difference?
I thought that there should be one more condition: standard deviation. Am
I right? In spss there is always some computation of confidence interval
for the population mean difference? How is it computed ? What is the
formla for computing this? Thanks a lot!

W.X.

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[Arthur Burke-2]

For details of how SPSS does the t-test, try ...

/Help/Statistics Coach/Compare Groups for Significant Differences/ ...
/T Test Algorithms

Art
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-----Original Message-----
From: Wang Xu [mailto:[hidden email]]
Sent: Tuesday, October 27, 2009 7:30 PM
To: [hidden email]
Subject: how to compute this?

Hi all list members,
   I am a green hand at data analysis. Recently I was bumped by a
scenario presented in a paper by Roger Kirk Kirk, R. E. (1996).
Practical Significance: A Concept Whose Time Has Come.
Educational and Psychological Measurement, 56(5), 746-759.
on the page 755 of the paper the 2nd paragraph there is it. The summary
of the scenario is as follows,
13 patients were assigned evenly to control and experimental
groups.t(10) =1.61, p=.14, the mean for experimetal group is 13 IQ
points higher than that of control group. At the end of the paragraph
the author said that a 95% confidence interval for the population mean
difference is likely to be between -6.3 and 32.3 IQ points. Do all the
present conditions necessiate the computation of confidence interval for
the population mean difference?
I thought that there should be one more condition: standard deviation.
Am I right? In spss there is always some computation of confidence
interval for the population mean difference? How is it computed ? What
is the formla for computing this? Thanks a lot!

W.X.

=====================
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