1. OTTFFSSENT ADGJM O{ne}T{wo}T{hree}F{our}F{ive}S{ix}, etc.
A{BC}D{EF}G{HI}J{KL}M

2. How Research Filters PerceptionY
Values, Theories,
Existing Research,
Methods

3. The Research Cycle

4. Measurement as Target Practice: Validity, Reliability, and Generalizability Compared
1.Not Valid, Not Reliable Not Valid, Reliable
x x
x x
3. Valid, Reliable Valid, Reliable, Generalizable (Target 2) xx xx
Validity, reliability, and generalizability may be explained by drawing an analogy between measuring a variable and firing at a bull’s-eye. In case 1, above, shots (measures) are far apart (not reliable) and far from the bull’s-eye (not valid). In case 2, shots are close to each other (reliable) but far from the bull’s-eye (not valid). In case 3, shots are close to the bull’s-eye (valid) and close to each other (reliable). In case 4, we use a second target. Our shots are again close to each other (reliable) and close to the bull’s-eye (valid). Because our measures were valid and reliable for both the first and second targets in cases 3 and 4, we conclude our results are generalizable.

5. Sampling Error
Because the sample measures fall within overlapping margins of error,
we must conclude that the measured difference in the popularity of the
two parties is not statistically significant.
48% 50%
Party A {----S---P-} % margin of error
Party B {-P---S----}
2.5 % margin of error
S=sample measure P=population measure

6. Turning a Classroom into a
Contingency Table
BACK
more than 10 hours TV per week and no act of physical violence per year
10 or fewer hours TV per week and no act of physical violence per year
LEFT RIGHT
10 or fewer hours TV per week and at least 1 act of physical violence per year
more than 10 hours TV per week and at least 1 act of physical violence per year
FRONT

7. TV Viewing By Aggressiveness

8. TV Viewing By Aggressiveness (men only)

9. Testing an Association for Spuriousness
(1) We believe there is a causal relationship between TV viewing and aggressiveness:
TV viewing Aggressiveness
(independent variable) (dependent variable)
(2) By controlling for gender we can see whether gender has created a spurious
association between TV viewing and aggressiveness:
TV viewing
(independent variable)
Respondent’s gender
(control variable)
aggressiveness
(dependent variable)
(association)
(association)
(no association)
(association)

10. Number of Sex Partners by Respondent’s Sex, USA, 1996 (in %)
respondent’s sex male female
number of sex partners
0 or
more than
total n

11. Number of Sex Partners by Respondent’s Sex, USA, 1996, Married People Only (in %)
respondent’s sex male female
number of sex partners
0 or
more than
total n

12. Correlation
Dependent variable Dependent variable Dependent variable
r = .85
r = -.92
r = 0
Independent Variable Independent Variable Independent Variable
1. Positive Correlation 2. Negative Correlation 3. No Correlation

13. Regression Analysis Y X y = a +bx, xxx x x x xx xx x xx
a is the value of the intercept,
b is the value of the slope,
y is the value of the dependent variable,
x is the value of the independent variable
xxx x x x xx xx x xx X

14. Multiple Regression Y Z b2
Y = a + b1x + b2z b1 a X

15. A Multiple Regression Equation
occupational prestige = -6.85
+ 1.36(income in $000s)
+ 4.14(years of formal education)
This means that at any level of education, an increase of $1,000/yr in income results in an average increase of 1.36 occupational prestige points. Also, at any level of income, an increase of one year of education results in an average increase of 4.14 occupational prestige points.