Soc midterm 2 vocab!

Population

the entire set of entities to which study findings are to be generalized

Sample

a subset of a population used to study the population

Representative sample

a sample that has the same distribution of characteristics as the population from which it was selected

Elements

the individual members of the population whose characteristics are measured

Sampling frame

the list of elements or sampling units from which the sample is selected.

• list all elements (roster of employees)

• a rule defining membership (area code)

Sampling units

units listed at each stage of a multistage sampling design. primary secondary and tertiary. ex: countries, neighborhoods, blocks, households

Inferential statistics

mathematical tool for estimating the likelihood that a statistical result derived from a probability sample is representative of the population

Sampling error

the difference between the characteristics of a sample and the characteristics of the population from which it was drawn

• depends on heterogeneity and sample size

How do you reduce sampling error?

INCREASE SAMPLE SIZE, ensure representative of population

What are the types of probability sampling methods?

1. simple random sampling

2. systematic random sampling

3. stratified random sampling

4. cluster sampling

Simple random sampling

Every element is selected on the basis of chance

• random number generator, lottery

• computer generated, random-digit dialing

Systematic random sampling

Every nth case in a list is selected for inclusion in the sample, where n is the sampling interval. N= population size divided by sample size. First element selected at random between 1 and n

Stratified random sampling

sample elements are selected separately and at random from population strata that are identified in advance

• reduces sampling error

• should be related to DV!

Proportionate stratified random sampling

elements are selected from strata IN PROPORTION to their representation in the population

Cluster sampling

cases are selected in 2 or more stages

1. random selection of naturally occurring clusters

   2. random selection of cases within clusters

What are the types of non-probability sampling?

1. Availability/ convenience sampling

2. snowball sampling

3. purposive sampling

4. quota sampling

Availability/ convenience sampling

elements are selected on the basis of convenience

Snowball sampling

individuals who have agreed to participate give researcher contact info for others who would be appropriate for the study

Purposive sampling

investigator relies on his/ her judgment to select units for a purpose often because the units are representative of the population

Quota sampling

similar to stratified random sampling but elements are chosen with convenience samples

Units of analysis

level social life on which a research question is focused. ex: individuals, couples, families, organizations, cities, etc.

Ecological fallacy

drawing conclusions about individuals with group level data

Reductionist fallacy

drawing conclusions about groups with individual level data

Nomothetic

relating to or dealing with abstract, general, or universal statements or laws.

Nomothetic causal explanation

establishing that change in the IV creates change in the DV

Idiographic

relating to or dealing with something concrete, individual, or unique

Idiographic causal explanation

the individual sequence of factors that create a specific outcome

Criteria for establishing nomothetic causality

1. association/ correlation

2. time order

3. nonspuriousness

Cross-sectional

data collected at one point in time

Longitudinal

data collected at 2 or more points in time

Repeated cross-sectional

(trend study) same population diff people

Panel study

going back to the same sample and population

Cohort study

Event-based study: people who experience an event at the same time (can be repeated cross-sectional or panel)

Mediator

a variable that creates a causal connection between the IV and DV. ex: parenthood—→work—→depression

Moderators

variables that affect the nature of the relationship between the IV and DV. Ex: age moderates the effect of time-out punishments on obedience.

Whats the best way to establish time order?

panel studies

How to establish nonspuriosness in survey research?

USE CONTROL VARIABLES

What does the variables in the experimental design notation mean?

R=random assignment

O=observation of the DV

X=treatment, IV

Posttest only control group design

R X O

R O

Pretest- Posttest only control group design

R O X O

R O O

Field experiments

true experiments carried out in a natural setting.

• increases internal validity

• difficult to carry out

• less control over uniformity

• less control over compliance

Factorial surveys

true experiments conducted through a survey, each having exposure to diff textual stimuli (vignette experiments)

Quasi experiments

an experimental design with a comparison group that wasn’t created with random assignment but is comparable in critical ways to the experimental group.

Nonequivalent control group design

O X O

O O

Time series control group design

O1O2O3………O30 X O31……….O60

Internal validity

sound evidence regarding the extent to which the IV has causal influence on the DV.

Threats to internal validity

1. history

2. maturation

3. testing

4. instrumentation

5. selection bias

6. differential attrition

7. expectancies of the experimental staff

8. placebo effect

How to address internal validity threats?

• a control group with random assignment

• double blind study

• Make experience in conditions as similar as possible to fix differential attrition

external validity

extent to which experimental findings are generalizable to other settings, subject populations and time periods

threats to external validity

caused by an interaction (moderation) between the treatment and some other feature of the experiment

How to address external validity threats?

 Replicate the study on a different subject pool, use a factorial survey so you can get a probability sample from population