Chapter 2

Question 1

Variable

Answer 1

A characteristic that can take on several or many different values.

Question 2

Measurement

Answer 2

The procedure for assigning a value to a variable.

Question 3

What are the types of variables?

Answer 3

Nominal, ordinal, interval/ratio.

Question 4

Nominal scale of measurement

Answer 4

Classifies objects into categories based on some characteristic of the object. E.g. nominal measurements of people could be male/female, political party, state they come from. Categories must be mutually exclusive. E.g. can’t be from WA and from NT.

Question 5

Ordinal scale of measurement

Answer 5

Classifies objects into mutually exclusive categories based on some characteristic of the object (as does nominal) and also requires that the classification has some inherent logical order. E.g. ordinal measurements of people could be freshman/sophomore/junior/senior, class rank, grade in course, level of depression.

Question 6

What are the characteristics of nominal level of measurement?

Answer 6

1. Categories are mutually exclusive.
2. The order of categories in a nominal variable is not important. It may be useful to assign a numerical value to a nominal category (e.g. 1=male, female=2) but doing that does not change that the order is irrelevant.

Question 7

What are the characteristics of an ordinal level of measurement?

Answer 7

1. Categories are mutually exclusive.

2. Categories have a logical order.

Question 8

What are the characteristics of an interval/ratio level of measurement?

Answer 8

1. Categories are mutually exclusive.
2. Categories have logical order.
3. Equal differences in characteristic imply equal differences in value.

Question 9

Interval/ratio level of measurement

Answer 9

Classifies objects into mutually exclusive categories based on some characteristic of the object (as does nominal and ordinal) and also requires that the classification has some inherent logical order (as does ordinal). Furthermore it requires that the width of all categories is the same. E.g. temperature measured in degrees celsius.

Question 10

Ratio scale

Answer 10

An interval scale of measurement that has a true zero point.

Question 11

Ratio level of measurement

Answer 11

You can separate ratio level measurement from interval measurement. It has all the characteristics of the interval level and it also requires that the scale have a true zero point.

Question 12

What is a true zero point?

Answer 12

Means that the thing being measured actually vanishes when the scale reads zero.

Question 13

Continuous variable

Answer 13

One with an infinite number of values between adjacent scale values. E.g. height

Question 14

Discrete variable

Answer 14

One with no possible intermediate values between two adjacent points. E.g. the number of children a woman has.

Question 15

Real limits of measurement

Answer 15

The points that are half the measuring unit above and below the measured value.

Question 16

Rounding

Answer 16

The procedure for abbreviating a number to determine the final digit.

Question 17

What is the rounding rule if the remainder is <5?

Answer 17

If the remainder is less than 500 simply discard the remainder. E.g. 8.347 becomes 8.3.

Question 18

What is the rounding rule if the remainder is >5?

Answer 18

If the remainder is greater than 500 add 1 to the last digit before the remainder and then discard the remainder. E.g. 4.86524 becomes 4.9.

Question 19

What is the rounding rule if the remainder is =5?

Answer 19

If the remainder is exactly 500 then use the even final digit and discard the remainder. E.g. 4.850 rounds down to 4.8.