Methods/Practices of POLS Exam 1

Units of analysis

the entities we want to describe and analyze

Individual-level unit of analysis

when a concept describes a phenomenon at its lowest possible level

Aggregate-level unit of analysis

a collection of individual entities

Cross-Sectional Data

data that represents many cases at the same or approximately the same point in time

Time-Series Data

One case over many points in time

Emprical

based on observation

Normative

description of what ought to be

Applied Research

a desire for application during the research

Theoretical Research

research that does not have a known or identified application as it drives motivation, but can be applied and occasionally have important benefits

Normative Theory

Show a design for some particular, desirable end

Formal Theory

application of mathematical techniques to a theory so that we might observe --> typically does not use real world data

Conceptual Definition

clearly describes the concept's measurable properties and specifes the units of analysis to which the concept applies

Operational Definition

describes the instrument to be used in measuring the concept and putting a conceptual definition "into operation"

Measurement Error: Systematic

sometimes the instrument used for measure procuces bias

Hawthorne Effect

the tendency for people to behave differently when they know they are being studied

Measurement Error: Random

Every possible outcome has an equal oppurtunity of occuring -- would not skew results

Instrument Reactivity

the affect an instrument has on the subjects

Reliability

consistency of measurement

Test-retest method

a method of calculating reliability by repeating the same measure at two or more points in time

Validity

the extent to which a test measures or predicts what it is supposed to

Face Validity

does the measure make sense?

Construct Validity

is the measure correlated with something that it should be?

Data

information collected

Datasets

where data is organized

Levels of Measurement

Interval, Ordinal, & Nominal

Nominal Level Variable

contains mutually exclusive values (I.e. religion, names, gender)

Ordinal Level Variable

mutually exclusive categories that are ranked or ordered -- do not know the exact distance between categories (I.e. rank 1, 2 or 3 ; agree or disagree with "--")

Interval Level Variable

mutually exclusive categories that are ranked or ordered with a known distance between them (I.e. age, income)

Variable

measured concept with at least two values

Indicator variable

A variable that takes on only one of two values, 0 or 1, based on a condition. Also referred to as a dummy variable.

Central Tendencies

mean, median, mode

Mode

most frequently occurring value (to get, check frequency & valid percent) --used for all three levels of measuremnt

Median

the middle score in a distribution; half the scores are above it and half are below it

Mean

average --used for ordinal and interval level variables

Dispersion

how spread out values are

standard deviation

a computed measure of how much scores vary around the mean score

Model

a simplfication of something -- always wrong but sometimes useful

Hypothesis

A testable prediction, often implied by a theory

Null Hypothesis

there is no relationship between the independent (x) and dependent (y) variables

Alternative Hypothesis (research hypothesis)

There is a relationship between x & y -- expression of the relationship you expect to see

Directional Hypothesis

States the direction of the difference or relationship

feeling thermometer

a visual aid that helps people quantify their feelings about people, ideas, and institutions

Template for writing a research hypothesis

In a comparison of [units of analysis], those having [one value on the independent variable] will be more likely to have [one value on the dependent variable] than will those having [a different value on the independent variable].

theory

a general statement about a causal relationship