1. BAILEY CHAPTER 3

2. TYPES OF RELATIONSHIPS
Bivariate relationships:
Strenght of relationships
Positive vs. negative relationships
Symmetrical rel.
Asymmetrical rel.
Linear vs. curvilinear
Spurious
intervening
Supressor
Specification variable

3. Strenght of relationship:
After we have established that two variables are indeed related the next question is how strongly they are related. İf two are related then we can predict the change in one looking at the change in the other.
The degree to which a prediction is correct (out of 100 predictions) is called strenghth of a relationship. Common stat for this is correlation., or Pearson’s product moment correlation coefficient. Varies between -1 and 1.

4. SYMETRİCAL VS. ASYMMETRİCAL RELATİONSHİPS
Symmetrical—change in one variable is asssociated with change in the other
In asymmetrical change in one variable is accompanied by change in the other but not vice versa. Smoking and cancer.
It is common in statistical lit to equate symmetrical relationships with explanation and asymmetricla relations with prediction.
İce cream eating ---- glove wearing (symmetrical)
Divorce-- number of cars sold (symmetrical)
alternative indications of the same variable
part of a common system

5. Asymmetrical:
smoking- lung cancer
gender -- tv watching
age-learning second language
time order (temporal sequence)
alterability (we know which one is dependent/independent)

6. SPURIOUS RELATIONSHIP
A relationship which two variables appear to be related only because a third variable is causing the occurence of both.
Employment tv watching
education
Nationalism conservatism
parenting style

7. + Sex tv watching + + less hours of work Intervening relationship:
Variables A and B might be highly correlated because A might cause C, and in turn C might cause B. +
Sex tv watching
less hours of work

10. SPECİFİCATİON VARİABLE:
Native language academic Success
gender is the specification variable.
CONCEPT OF CAUSALITY
Associaton vs. causation.
X causes Y if;
there is relation between X and Y.
Asymmetrical
a change in X results in a change in Y regradless of other factors.

11. 3 combinations:
Necessary but not sufficient:
X is necessary but not sufficient for the existence of Y.
Flour is necessary but not sufficient to bake a cake. We need other ingredients.
X must occur before Y occurs, but X alone not enough to cause Y.
Chemical makeup __________ depression
sufficient but not necessary
X and Z are alternative causes of Y. Not partial causes. Each is sufficient to cause Y by itself, but they are alternatives.
High speed ___________________traffic accident
Drunk driving _________________traffic accident
X is both necessary and sufficent simultenously for Y.
Y will never exist unless X exists, and will always exist when X exists. X is the complete and the only cause.