Confidence Interval Flashcards
The most frequently advocated alternative to NHST is
to report effect sizes with confidence intervals.
Can CIs be used a an approach to statistical tests?
No, but used with NHST
What do CIs provide?
With a degree of certainty, the range within which a population value is likely to fall given sampling error.
What does a 95% CI mean? (100 sample ex.)
if we were to take 100 samples, we expect that for 95 of those, the mean would be within a given range.
Obtain confidence interval
To obtain this confidence interval, add and subtract the margin of error from the sample mean. This result is the upper limit and the lower limit of the confidence interval.
statistically significant for Ci
A statistically significant result is where the null hypothesis is outside of the CIs.
Ci definition
Communicated how accurate our estimate is likely to be
Variation
Greater variance leads to wider Ci
Small samples =
More variation
Large sample =
Smaller confidence level
If Ci = 95%, we can be sure that ..
The true parameter lies within interval
1.96
= z value for 95% Ci
Bigger confidence level =
Wider width
Bigger sample =
Narrow Ci
Bigger standard deviation
- bigger Ci
