Class Notes (835,727)
Canada (509,353)
Sociology (1,100)
SOCY 211 (69)
Carl Keane (12)

SOCY211 Week 7, Lecture 1

6 Pages
Unlock Document

SOCY 211
Carl Keane

NOMINAL MEASURES OF ASSOCIATION FOR TABULAR DATA - Measures of association for nominal level variables will range from 0 to 1.0. - Measure near 0 suggests no association between the variables - Something close to 1.0 has a strong relationship/association - If you get an association of 0.30 or larger it is a strong association (for nominal level) - 0.11 up to 0.30 has a moderate degree of association between the two variables - Anything less than 0.10 is a weak association - Three most common ones for nominal level measurements: • Phi φ • Cramer’s V • Lambda λ - Phi is reported if the table has 2 rows and 2 columns, while V and Lambda can be used for tables of any size. - Phi and V are called:  Symmetric Measures of Association -Phi and V are based on the value of Chi-Square -Phi and V are based on the value of Chi-Square. So, if the chi-square value is statistically significant, so too will be Phi and V. - Phi and V have the same problems that you find with Chi Square χ² Phi = √ ---- N EXAMPLE (statistically significant) Gender and Crime Victimization Chi-Square Tests Value df Asymp. Sig. Exact Sig. Exact Sig. (1-sided) (2-sided) (2-sided) Pearson Chi- 12.792 1 .000 Square To compute Phi: 12.792 Phi = √-------- 1,520 Phi = √0.00842 Phi = 0.0917 (0.092) -Output that we get is given in a table You also get the level of significance 1 Gender and Victimization Symmetric Measures Value Approx. Sig. Nominal by Nominal Phi .092 .000 Cramer's V .092 .000 N of Valid Cases 1520 -Strength of the association between these two variables even if it is statistically significant is the same -This is because the formula for Cramer’s V is essentially the same -The formula for Cramer’s V is: χ² V = √ --------------------- (N) (min r-1, c-1) (min r-1, c-1) = the minimum value of the number of rows minus one, or the number of columns minus one So, in our case: 12.792 V = √ --------------------- (1520) (2 – 1 or 2 – 1) 12.792 V = √ -------------------- (1520) (1) V = 0.092 LAMBDA λ (Guttman’s Coefficient of Predictability)  Asymmetric Measure of Association -The value of Lambda will depend on which variable is independent and which is dependent -Also differs because Lambda is NOT Chi-square based -Doesn’t have the same limitations or problems -Referred to as: “Proportional Reduction in Error” (PRE) -For this, at first you predict something without knowing anything about the independent level -Then you are given information about the independent variable - If two variables are related your level of predictability should increase - Knowing the independent variable should reduce the number of errors 2 EXAMPLE: *Table is larger than two by two so we ignore Phi Gender and feelings of safety You walking alone at night in your area * Sex Crosstabulation Sex Total Male Female You Very safe? Count 422 154 576 walking alone at night in your area % within Sex 52.8% 21.4% 37.9% % of Total 27.8% 10.1% 37.9% reasonably Count 307 344 651 safe? % within Sex 38.4% 47.7% 42.8% % of Total 20.2% 22.6% 42.8% somewhat Count 40 119 159 unsafe? % within Sex 5.0% 16.5% 10.5% % of Total 2.6% 7.8% 10.5% very Count 20 41 61 unsafe? % within Sex 2.5% 5.7% 4.0% % of Total 1.3% 2.7% 4.0% does not Count 10
More Less

Related notes for SOCY 211

Log In


Join OneClass

Access over 10 million pages of study
documents for 1.3 million courses.

Sign up

Join to view


By registering, I agree to the Terms and Privacy Policies
Already have an account?
Just a few more details

So we can recommend you notes for your school.

Reset Password

Please enter below the email address you registered with and we will send you a link to reset your password.

Add your courses

Get notes from the top students in your class.