lecture 3 & 4

Question 1

explanatory theory

Answer 1

a set of internally consistent statements about relationships between concepts linked by mechanisms.
i.e. an explanation about why something is observed—what caused this particular phenomenon?
e.g. Why is voter turnout for local elections higher in some cities than in others?

Question 2

ratio variable

Answer 2

quantitative variable with an ordered scale and equal intervals, where there is a true 0 point
0 means zero e.g. income

Question 3

interval variable

Answer 3

type of quantitative variable that is measured on a scale where the intervals between values are consistent and meaningful, but the variable lacks a true zero point.
0 does not mean zero e.g. temperature

Question 4

discrete variable

Answer 4

Possible values are clearly separated (e.g. count variables: number of children)

Question 5

continuous variable

Answer 5

“in-between values” are always possible (e.g. temperature of 27.873425 Celsius).

Question 6

dependent variable

Answer 6

the characteristic you wish to explain (outcome variable)
caused or depends upon the IV
example: voter turnout

Question 7

independent variable

Answer 7

the explanation or one of the explanations (explanatory variable)
Influence, affect or cause some other phenomenon
Example: bad weather on voting day, distance to the voting station

In simple terms, we can think of the IV (x) causing the DV (y):
x → y
Independent variable → Dependent variable

Question 8

what type of variable is the duration of an interview

Answer 8

quantitative variable/ continuous variable

Question 9

what type of variable is a favourite coffee brand

Answer 9

nominal variable

Question 10

what type of variable is the level of democracy

Answer 10

ordinal variable

Question 11

hypothesis

Answer 11

an educated guess that indicates how an IV is thought to affect, influence or alter a DV
Proposes a relationship that subsequently will be tested with empirical observations of the variables

Question 12

The entity/unit of analysis

Answer 12

The entity that we are analysing, the entity to which the research questions and hypotheses refer. e.g. individuals, cities, countries, elections, wars. .

Question 13

measurement error is due to

Answer 13

• Difficulty in obtaining accurate and complete data (e.g. Historical casualties in war).
• Changes in the measurement formula (e.g. GDP changes suddenly).
• Interpretation of questions, e.g. Are you “happy”?

Question 14

two main types of measurement error

Answer 14

1. Random: the unpredictable fluctuation in measurements due to chance or random factors.e.g. measuring the weight of an object on a balance scale, and due to air currents or small variations in the scale’s precision, the readings fluctuate slightly around the true weight.
2. Systematic: a consistent and reproducible deviation of measurements from the true value.
   Unlike random errors, systematic errors do not cancel out with repeated measurements; instead, they consistently skew the results.
   Example: If a scale consistently reads 1 kg higher than the true weight of an object due to a calibration error, it introduces a systematic error.

Question 15

validity of research design

Answer 15

Must be:
1. Appropriate: The number of teachers in city schools is an inappropriate measure of the quality of public education
2. Complete: student/teacher ratio is appropriate but incomplete: quality of education is also a function of libraries, facilities, etc.