Zusammenfassung der Ressource
Statistical Inference Basics
- Inferential statistics
- Used to determine what
happens if we conduct the
same study multiple times
- Statistically significant
- Group differences
are due to random
error or the variable
- Significance level
- Also alpha level
- How willing are you to be wrong
- Research hypothesis
- General hypothesis stating a relationship
- Null hypothesis
- States that the
population means are
equal
- Example statistical tests
- T test
- Allows you to determine
whether the mean difference
came from the null hypothesis
- Reflect all possible outcomes if we
compare the means of the two groups
and the null hypothesis is true
- T = group difference/within group variability
- Degrees of freedom
- Adjustment used to account
for the fact that we are
estimating population values
- One tailed test
- When the research hypothesis
specified a direction of difference
- Two tail hypothesis
- Research hypothesis did not
specify a predicted direction of
difference
- F test
- Used when there are
more than two levels of
an independent variable
- Ratio of systematic and error variance
- Systematic variance
- Deviation of group mean from grand mean
- Error variance
- Deviation of individual scores from the group means
- Errors
- Type I errors
- When we reject the null
hypothesis, but it is true
- Type II errors
- When the null hypothesis is retained
based on sample data, but is false
- Worse than Type I errors
- Power analysis
- Related to the likelihood
that you will retain a null
hypothesis that is false
- Confidence intervals
- When they do not overlap,
the results are most likely
statistically significant
- Conclusion validity
- Extent to which the
conclusions on the
relationships are correct