Chapter 5: Identifying Variables

Question 1

Characteristics of a Variable

Answer 1

• property that takes on different values
• image, perception or concept that can be measured
• something that can change and is typically the focus of the study
• anything that can vary

Question 2

Difference between Concept and Variable

Answer 2

• main difference: measurability

Concept: mental images or perceptions and their meanings vary from individual to individual
- subjective impressions

Variable: Measurable with varying degrees of accuracy depending upon the measurement scale

• Concepts must be converted into variables for subjective measurement

Question 3

Converting Concepts into Variables

Answer 3

• identify indicators of the concepts that can be converted into variables

Question 4

Types of Variables

Answer 4

1. the causal relationship
2. the study design
3. the unit of measurement

Question 5

Independent Variable

Answer 5

Cause supposed to be responsible for the changes in a phenomenon

Question 6

Dependent Variable

Answer 6

Outcome/change that is caused by the introduction of the independent variable - RESULT

Question 7

Extraneous Variable

Answer 7

Factors influencing in real-life situations that may change the dependent variable

Question 8

Intervening Variable

Answer 8

Links the independent and dependent variable. Mediated relationship between two variables

Question 9

Active Variables

Answer 9

Variables that can be changed, manipulated or controlled

Question 10

Attribute Variables

Answer 10

Variables that cannot be manipulated, and that reflects the characteristics of the study population

Question 11

Ways of categorizing variables

Answer 11

1. measurement categorical or continuous

2. qualitative or quantitative

Question 12

Categorical Variables

Answer 12

• measured on ordinal or nominal scales
• constant variable: has only one category: water, tree
• dichotomous variable: has only two categories: female/male
• polytomous variable: has more than two variables: high, average, low

Question 13

Continuous Variables

Answer 13

• can take any value in the scale they are measured
• age, can be measured in years, month or days
• measured by interval or ratio scales

Question 14

Measurement Scale Qualitative

Answer 14

• use descriptive statements

Question 15

Measurement Scale Quantitative

Answer 15

• usual on measurement scales (ratio, normal, ordinal, or interval)

Question 16

Nominal or Classificatory Scale

Answer 16

• classification based on a common/shared property or characteristic
• nominal variable may have more subcategories
• gender: two subgroups - female/male
• political parties: several subgroups (parties)

Question 17

Classification of levels of Measurement by S. Stevens

Answer 17

• Nominal scale
• ordinal or ranking scale
• interval scale
• ratio scale

Question 18

Ordinal or Ranking Scale

Answer 18

• all properties of the nomial scale, but also ranks subgroups in a certain order
• above average, average, below average

Question 19

Interval Scale

Answer 19

• all characteristics of ordinal scales
• subcategories are arranged an ascending/descending order
• uses unit of measurement
• Temperature

Question 20

Ratio Scale

Answer 20

• all the properties of the other scales, but has also a starting point at 0