Sample Surveys

Question 1

The entire group of individuals or instances about whom we hope to learn.

Answer 1

Population

Question 2

A representative subset of a population, examined in hope of learning about the population.

Answer 2

Sample

Question 3

A study that asks questions of a sample drawn from some population in the hope of learning something about the entire population, such as opinion polls.

Answer 3

Sample survey

Question 4

Any systemic failure of a sampling method to represent its population is this.

Answer 4

Bias

Question 5

Bias sampling methods tend to over or under estimate parameters.

1. relying on voluntary response
2. undercoverage of the population
3. nonresponse bias
4. response bias

Answer 5

4 common sources of bias

Question 6

The number of individuals in a sample determines how well the sample represents the population, NOT THE FRACTION OF THE POPULATION SAMPLED.

Answer 6

Sample Size

Question 7

The best defense against bias–in which each individual is given a fair, random chance of selection.

Answer 7

Randomization

Question 8

A sample that consists of the entire population.

Answer 8

Census

Question 9

A numerically valued attribute of a model for a POPULATION, estimated from sampled data.

Answer 9

Population parameter

Question 10

Statistic

Answer 10

Values calculated from sampled data, usually those that correspond to, and thus estimate, a population parameter. (also called sample statistic)

Question 11

A sample is said to be this if the statistics computed from it accurately reflect the corresponding population parameters.

Answer 11

Representative

Question 12

A sample in which each set of n elements in the population has an equal chance of selection.

Answer 12

Simple Random Sample (SRS)

Question 13

The natural tendency of randomly drawn samples to differ, one from another.

Answer 13

Sampling Variability

Question 14

A sampling design in which the population is divided into several subpopulations from which random samples are drawn.

Answer 14

Stratified random sample

Question 15

A sampling design in which entire heterogeneous groups are chosen at random. Usually selected for as a matter of convenience, practicality, or cost.

Answer 15

cluster sample

Question 16

Sampling schemes that combine several sampling methods.

Answer 16

Multistage sample

Question 17

A sample drawn by selecting individuals systematically from a sampling frame.

Answer 17

Systematic sample

Question 18

A small trial run of a survey to check whether questions are clear.

Answer 18

Pilot study

Question 19

A sample in which individuals can choose on their own whether to participate–these are always invalid, no matter how large the sample size.

Answer 19

Voluntary Response Sample

Question 20

Bias introduced to a sample when individuals can choose on their own whether to participate in the sample.

Answer 20

Voluntary Response Bias

Question 21

This consists of the individuals who are conveniently available.

Answer 21

Convenience Sample

Question 22

A sampling scheme that biases the sample in a way that gives part of the population less representation in the sample than it has in the population.

Answer 22

Undercoverage

Question 23

This type of bias is introduced when a large fraction of those sampled fails to respond.

Answer 23

Nonresponse bias

Question 24

Anything in the survey design that influences responses falls under the heading of this.

Answer 24

Response bias

Question 25

Sampling Frame

Answer 25

This is a list of individuals from which an SRS (simple random sample) is drawn, for example a list of registered full-time college students.

When defining the Sample Frame, consider pertinent details of the population under consideration.