Chapter 8: Bivariate Correlational Research Flashcards
What is the difference between experimental methods and correlation?
- Experimental methods test if changes to IV causes changes to DV score. Ex. Does coffee make you anxious?
- Correlations are descriptive methods. Look at behaviors as they occur. Ex. Is there a relationship between feeling anxiety (X) and coffee drinking (Y)?
What do correlations do?
- Evalulate the strength of a relationship
- The mathematical measure of an association between 2 variables
- Do NOT establish cause
When would you use a correlation?
- To make a prediction
- For validity: If you made a new IQ test, to determine how good it is, you could compare results on the new test (X) to results on another valid test (Y)
- For reliability: Measurements are stable if they produce similar results across situations. Ex. To see if your score today is correlated with your score next week
What are some association claims supported by correlational research? Why aren’t they causal statements?
- Meaningful conversations linked to happier people
- Couples who meet online have better marriages.
- Tehse are not causal statements because there was no random assignment to different groups
Bivariate correlation/association
- Three kinds: pos, neg, zero
- 2 variables (X and Y). Each participant will have a score on both variables. Asks: Is there a relationship between the way one variable changes and the way a second variable changes?
What does a scatterplot do?
Represents the score for each participant on both variables
Cacioppo et al, 2013
- Found that ouples who meet online tend to have between marriages.
- Emailed surveys asking “How did you meet?” and the Couples Satisfaction Index (CSI)
- 19,000 respondents… people who met online tended to score slightly higher on CSI
What two pieces of information does the corrleation coefficient tell you?
- Strength of the correlation
- Direction of the correlation
Is a value between -1 and 1
How does the correlation coefficient (r) tell you the strenght of the correlation?
- Closer to +/-1.0= strong relationship
- Closer to +/- 0.01= weak relationship
How does the correlation coefficient (r) tell you the direction of the correlation?
- Positive: values increase and decrease together
- Negative: one value increases, the other decreases
How to visualize associations with categorical data?
- Ex: Did you meet online? Categories are yes and no.
- Scatter plots can still be useful, as you can seee a higher density of dots in online.
- But bar graphs are usually more helpful for categorical variables
Do correlational studies establish internal validity?
NO
What is construct validity?
- the degree to which a test or measurement tool accurately assesses the theoretical concept or “construct” it is intended to measure
How can you determine construct validity of association claims?
- Because association claims describe the relationship between 2 variables, it is reasonable to ask about the construct validity of each variable.
- Can ask: How well were each of the variables measured? Does the measure have good reliability? Is it measuring what it intends to measure? Face, discriminant, and convergent validity?
Using the CSI example, what questions should you ask to determine its’ construct validity?
- Does it have good internal reliability?
- Does it correlate with other measures of marital happiness?
What is face validity?
- Compared to construct validity, which examines whether the tool truly captures the underlying theoretical construct, face validity is a more superficial assessment based on how the tool appears on the surface
- Face validity is a subjective evaulation of whether a test “looks like” it measures what it intends to