W3: RQ for Associations (Page 22-34)

Question 1

What is the margin of error in confidence intervals. Are they symmetrical?

Answer 1

Margins of Error:
Lengths from the sample estimates to the lower bound and to the upper bound.

They are asymmetric around sample estimates

Question 2

What is a contingency table

Answer 2

A (two-way) contingency table contains frequency counts of how many people belong jointly to each category of one variable and each category of a second variable

Question 3

What does a joint cell in a contingency table contain

Answer 3

Frequency count of all participants who belong to Variable A AND B (keyword: And)

Question 4

What is the row and column variable on a contingency table called

Answer 4

Marginal Cells

Question 5

What can help us understand a two-way table

Answer 5

Mosaic Plots

Question 6

How do we analyse a contingency table

Answer 6

Chi-Squared Null Hypothesis Test (Bio Psych)

Question 7

What is a Cramer’s V

Answer 7

Measure of strength of association in contingency table, where at least 1 variable has 3 + categories

Question 8

What does the Cramer’s V measure and what does it not measure

Answer 8

Strength of association, not Direction (no intrinsic ordering to 3/more categories)

Question 9

What is the value of Cramer’s V range

Answer 9

Between 0 to 1. Closer to 1 = Stronger Association

Question 10

Is Cramer’s V a sample statistic or a population parameter

Answer 10

It can be both a sample statistic and a population parameter

Question 11

Does Cramer’s V use words like significant? What are some issues raised in the lecture?

Answer 11

No use of words like significant
No use of words like no association
No P value (Cramar’s Value does not provide, CI is more informative)

Question 12

What is an estimator

Answer 12

An estimator is the mathematical function applied to our sample scores to obtain an estimated value for a population parameter (Formula to get summary characteristic)

Question 13

if an estimator calculates a sample statistic value, it is called ___

Answer 13

point estimator

Question 14

if an estimator calculates a confidence interval, it is called ___

Answer 14

interval estimator.

Question 15

How many estimators are there for the same population parameter

Answer 15

Can be multiple

Question 16

How can estimators of a population parameter vary in 3 properties. FIRST WAY

Answer 16

1. ) 95% UNBIASED INTERVAL ESTIMATOR captures the true population parameter value 95% of the time on average over the long run
   - If it does not, it is biased. Biasness does not depend on sample size

Question 17

How can estimators of a population parameter vary in 3 properties. SECOND WAY

Answer 17

2.) 95% CONSISTENT INTERVAL ESTIMATOR gets increasing closer to capturing the true population parameter value 95% of the time on average over the long run as sample size increases.

– If it does not, it is inconsistent. Consistency relates to sample size

Question 18

How can estimators of a population parameter vary in 3 properties. THIRD WAY

Answer 18

3.) 95% interval estimator of a population is MORE EFFICIENT if it produces a more narrow confidence interval on average over the long run compared to some competing estimator

Question 19

How can estimators of a population parameter vary in 3 properties. Summary

Answer 19

1. ) Biasness
2. ) Consistency
3. ) Efficiency

Question 20

what is the ideal interval estimator. What sometimes happens

Answer 20

Unbiased, Efficient, Consistent.

Sometimes, a consistent efficient estimator (maybe bias) > unbiased inefficient estimator

Question 21

What are correlations and cramer’s V examples of

Answer 21

Effect Sizes

Question 22

What are effect sies

Answer 22

Umbrella term used for any quantitative measure of strength of relationship between construct measures.

They are estimated by sample statistics and can be applied to population parameters. More useful when accompanied by confidence intervals.

Question 23

When both variables in a contingency table contain 2 categories, what is often used to report effect size

Answer 23

Odds Ratio

Question 24

What are odds ratio

Answer 24

Measure of strength of association between 2 variables both containing 2 categories.

Ratio of 2 sets of odds formed by considering odds of one category in a variable within each category of the other variable

Question 25

What are odds

Answer 25

Probability of one event/category occuring relative to probability of it not occuring

Question 26

What happens to odds ratio if category order on one variable was reversed

Answer 26

The value will just be a reciprocal

Question 27

When we have an odds ratio <1, what do we usually do

Answer 27

1. ) Reverse ordering of two categories in one of the variable in a contingency table
2. ) Recalculate odds ratio in revised table and interpret the estimate which will >1