Tests of Relationships- Correlation; Regression Flashcards
The questions below test _________ or __________.
- Is group A different from group B?
- Does this treatment cause this outcome?
Difference or proportions depending on the outcome variable type.
- Test difference for _________ outcomes.
- Test proportions for ________ outcomes.
- continuous
- categorical
The questions below test _____________.
- What is the relationship between A and B?
- Does variable A increase with variable B?
relationship
Examples:
Which tests would be appropriate for the following questions?
- ) Is the male group different from the female group by their BMI level?
- ) Is the gender linked to a certain age group?
- ) What is the relationship between BMI and DBP at baseline?
- ) Test the difference of the mean BMI between groups of male and female.
- ) Compare the proportions of being older than 50 yrs between the groups of male and female.
- ) Test relationship between DBP and BMI.
Tests of Differences (parametric vs non-parametric):
-What 2 tests are used for two group independent comparison? Which is used for parametric data? Which is used for non-parametric data?
- What 2 tests are used multi group independent comparison? Which is used for parametric data? Which is used for non-parametric data?
- What 2 tests are used two group paired comparison? Which is used for parametric data? Which is used for non-parametric data?
- What 2 tests are used for multi group paired comparison? Which is used for parametric data? Which is used for non-parametric data?
- Independent t-test, Mann-Whitney U Test
- Independent t-test = parametric
- Mann-Whitney U Test = non-parametric
- ANOVA, Kruskal-Wallis H Test
- ANOVA = parametric
- Kruskal-Wallis H Test = non-parametric
- Paired t-test, Wilcoxon Signed Rank Test
- Paired t-test = parametric
- Wilcoxon SIgned Rank Test = non-parametric
- Repeated Measures ANOVA, Friedman Test
- Repeated Measures ANOVA = parametric
- Friedman Test = non-parametric
Tests of Proportions (parametric vs non-parametric):
-What 2 tests are used for two group independent comparison? Which is used for data that isn’t sparse? Which is used for sparse data?
- What 2 tests are used for multi group independent comparison? Which is used for data that isn’t sparse? Which is used for sparse data?
- What 2 tests are used for two group paired comparison? Which is used for data that isn’t sparse? Which is used for sparse data?
- What 2 tests are used for multi group paired comparison? Which is used for data that isn’t sparse? Which is used for sparse data?
- Chi-Square, Fisher’s Exact
- Chi-Square = data not sparse
- Fisher’s Exact = data sparse
- Chi-Square, Fisher’s Exact
- Chi-Square = data not sparse
- Fisher’s Exact = data sparse
- McNemar Test, McNemar Exact Test
- McNemar Test = data not sparse
- McNemar Exact Test = data sparse
- Stuart-Maxwell Test, Generalized Stuart-Maxwell
- Stuart-Maxwell Test = data not sparse
- Generalized Stuart Maxwell = data sparse
Tests of Cerrelation; Regression:
1
- Correlation is when you look at the ____________ between two variables.
- Draw a ______________ to visualize
- Compute a ________________ to quantify
- relationship
- scatter plot
- correlation coefficient (r)
_____________ is a way of visualizing the relationship between two variables. Each point represents the intersection of a pair of related observations. They can visually clarify the _______ and shape of a relationship.
- Scatter plot
- strength
________ _________ is a decimal number in the range of -1 to +1 and is a measure of linear relationships between two variables.
Correlation coefficient (r)
- What is a perfect positive correlation value?
- What is a perfect negative correlation value?
+1
-1
With correlation coefficient:
- The sign of r indicates __________.
- The absolute value of r indicates __________.
- direction
- strength
- How do we interpret correlation coefficient (r) values?
- Should these values be used as strict cutoff points? Why or why not?
- 0-0.25 = little or no relationship
- 0.25-0.50 = fair
- 0.50-0.75 = moderate to good
- 0.75-1 = good to excellent
-No, because they are affected by sample size, measurement error, and the types of variables beinig studied.
Correlation coefficient is a measure of ________ relationship only. It cannon be used for _____________ relationship.
- linear
- curvilinear
What are 4 types of correlation coefficients?
- Pearson (Product-Moment)
- Spearman Rank
- Phi
- Point Biserial