Question

1. ) Identify the independent and dependent variables in the following experiments :

a) a teacher gives stickers for good behavior to students in one of her classes and uses verbal approval alone to reward good behavior in a second class. she later compares the conduct of grades of students in her two classes.

b) a researcher injects one group of rats with a drug and gives rats in a second group a saline solution. four hours later he compares the maze-learning performances of the rats in the two groups, measured by number of trials to perfect performance.

2.) Identify each of the following measurement levels as nominal, ordinal, interval or ratio :

a) educational attainment, scored 0=no high school diploma. 1 = high school graduate, 2 = associates degree, 3 = bachelors degree, 4 = masters degree, 5 = doctorate

b) attitudes towards a proposed tax, scored 0= oppose, 1 = favor

c) academic performance, measured as ones ranking in the class

d) obesity, measured as body fat

Answer 1

Question 1

a) Dependent variable - stickers

Independent variable - good behavior

b) Dependent variable - maze-learning performance

Independent variable - drug and saline solution

Question 2

a) Ordinal (since the data is placed in an order from high school graduate to doctrate )

b) Nominal (since the values are used for labeling and doesn't have any quantitative value)

c) Ordinal (since the order of values is important as students are ranked from first to last)

d) Interval (BMI value which measures obesity is a continuous variable)