EDUS 608

Question 1

Variable (Definition)

Answer 1

a characteristic that can vary in value among subjects in a sample or population.

Question 2

Categorical Variable (Qualitative)

Answer 2

scale for measurement is a set of categories. Examples: Racial-ethnic group (white, black, Hispanic) Political party identification (Dem., Repub., Indep.) Vegetarian? (yes, no) Happiness (very happy, pretty happy, not too happy) Gender Religious affiliation Major

Question 3

Nominal Scale

Answer 3

A type of Categorical Variable with unordered categories. Examples: Preference for President, Race, Gender, Religious affiliation, Major Opinion items (favor vs. oppose, yes vs. no)

Question 4

Ordinal Scale

Answer 4

A type of Categorical Variable with ordered categories. Examples: Political ideology (very liberal, liberal, moderate, conservative, very conservative) Anxiety, stress, self esteem (high, medium, low) Mental impairment (none, mild, moderate, severe) Government spending on environment (up, same, down)

Question 5

Quantitative Variable (Definition)

Answer 5

A set of possible values is called an interval scale (i.e. numerical interval between each possible pair of values) The difference between values are consistent: -Moving from $20,000 to $21,000 is the same magnitude as moving from $50,000 to $51,000 -Moving from 90 degrees F to 95 degrees F is the same as moving from 70 to 75

Question 6

Skewed Distribution (Describe)

Answer 6

Mean is drawn in direction of longer tail, relative to the median.

Question 7

The following is an example of: e.g., Grades A,B,C,D,E an ordinal scale, but treated as interval if assign scores 4,3,2,1,0 to construct a GPA)

Answer 7

Note: In practice, ordinal categorical variables often treated as interval by assigning scores

Question 8

What is Descriptive Statistics?

Answer 8

1. Describing data with tables and graphs (quantitative or categorical variables) 2. Numerical descriptions of center (mean/median) and variability (standard deviation/ variance) (quantitative variables)

Question 9

Frequency distribution

Answer 9

Lists possible values of variable and number of times each occurs. = 60) Ex. Student survey (n “political ideology” measured as ordinal variable with 1 = very liberal, …, 4 = moderate, …, 7 = very conservative

Question 10

Histogram

Answer 10

Bar graph of frequencies or percentages.

Question 11

Bell-shaped Histogram