# Help with confidence interval and interpreting data!?

#### OscarDaGrouch

##### New Member
Someone please please help me make sense of these stats! I really need help with interpreting outcome of studies! How do i calculate CIs (no need to know actual calculation as can use calculator) and make sense of outcome... Any help would make me forever grateful!

STUDY 1.
Pre- and post-intervention values (standard error).
Intervention n=235
Mean (SD) Pre-test 6.66 (0.15)
Mean (SD) Post-test 5.74 (0.17)
P value* <0.0001

Waiting room control n=96
Mean (SD) Pre 6.31 (0.26)
Mean (SD) Post 6.39 (0.27)
P value* <0.516

*Significance of pre- to post-intervention change.

STUDY 2 n=59
Pre- and post-intervention values (standard error).
Intervention
Mean (SD) Pre-test 3.15 (2.8)
Mean (SD) Post-test 2.47 (2.6)

Difference -0.69
t -3.30
p 0.001

Significance set at <0.05.

Experiment wide alpha was set at p< 0.05 such that each test had to reach a level of p <0.004 (0.05/13) to be considered statistically significant.; one-tailed. One-tailed tests were used for hypothesis testing.

I am looking at the overall success of the intervention and have to use just these two papers to discuss the intervention itself. I need to discuss the p values which I understand, but also the CIs! I need to make sense of both CIs and what this means to the actual intervention… Hope this makes sense!

#### Karabiner

##### TS Contributor
But CI's are nowhere mentioned in what you cited.
BTW, p < 0.01 and a 99% CI not containing then
value 0 have the same meaning. So interpreting
the CIs won't add much information to the interpretation
of p values.

With kind regards

K.