Sampling and Experimentation

Question 1

Population

Answer 1

The entire group of individuals or items of interest

Question 2

Sampling Frame

Answer 2

A list of all members of the population

Question 3

Sample

Answer 3

The part of the population that is being examined

Question 4

Sample Survey

Answer 4

The process of collecting information from a smaple

Question 5

Census

Answer 5

The process of collecting information from all units in a population

Question 6

Observational Study

Answer 6

An activity in which the experimenter observes the relationship among variables rather than creating them

Question 7

Experiment

Answer 7

A activity in which the experimenter applies treatments to subjects to see a relationship between variables

Question 8

Confounding Factor

Answer 8

Occurs when the two variables of interest are related to a third variable instead of just to each other

Question 9

Biased Sampling

Answer 9

Result in values that are systematically different from the population values or favor certain outcomes

Question 10

Judgmental Sampling

Answer 10

Makes use of a nonrandom approach to determine which item of the population is to be selected in the sample

Question 11

Sample of Convenience

Answer 11

A sample that is rather easy to obtain

Question 12

Volunteer Samples

Answer 12

The subjects choose to be a part of the sample

Question 13

Simple Random Sampling (SRS)

Answer 13

A process of obtaining a sample from a population in which each member has an equal chance of being selected

Question 14

Types of Simple Random Samples

Answer 14

1. Sampling with replacement from a finite population

2. Sampling without replacement from an infinite population

Question 15

Systematic Sampling

Answer 15

The first item is selected at random from the first k items in the frame, and then every kth item is included in the sample

Question 16

Stratified Random Sampling

Answer 16

The population is divided into groups called strata and a simple random sample is taken from each stratum

Question 17

Proportional Sampling

Answer 17

The population is divided into groups called strata and a simple random sample of size proportional to the stratum size is selected from each stratum

Question 18

Cluster Sampling

Answer 18

A population is divided into non-homogeneous groups called clusters and a simple random sample is obtained from some clusters but not all of them

Question 19

Sampling Error

Answer 19

Variation inherent in any survey

Question 20

Response Bias

Answer 20

Caused by the behavior of the interviewer or respondent

Question 21

Non-response Bias

Answer 21

Occurs if the person selected for an interview cannot be contacted or refuses to answer

Question 22

Under-coverage Bias

Answer 22

Occurs if part of the population is left out of the selection process

Question 23

Wording Effect Bias

Answer 23

Occurs is confusing or leading questions are asked

Question 24

Response/Dependent Variable

Answer 24

The variable to be measured in the experiment

Question 25

Explanatory/Independent Variable

Answer 25

A variable that may explain the differences in responses

Question 26

Experimental Unit

Answer 26

The smallest unit of the population to which the treatment is applied

Question 27

Confounding Variable

Answer 27

A variable whose effect on the response cannot be separated from the effect of the explanatory variable

Question 28

Factor

Answer 28

A variable whose effect on the response is of interest in the experiment

Question 29

Levels

Answer 29

The values of a factor used in the experiment

Question 30

Treatments

Answer 30

The factor-level combinations used in the experiment

Question 31

Control Group

Answer 31

A group of experimental units similar to all the other experimental units except that it is not given any treatment

Question 32

Placebo Group

Answer 32

A control group that receives a placebo in experiments involving medicines

Question 33

Blinding Technique

Answer 33

Used in experiments to prevent bias

Question 34

Single-Blind Experiment

Answer 34

Either the patient does not know which treatment they are receiving or the person measuring the patient’s reaction does not know which treatment was given

Question 35

Double-Blind Experiment

Answer 35

Both the patient and the person measuring the patient’s reaction do not know which treatment the patient was given

Question 36

Blocking

Answer 36

Used to control the effects of known factors

Question 37

Block

Answer 37

A group of homogeneous experimental units

Question 38

Replication

Answer 38

Refers to the process of giving a certain treatment numerous times in an experiment or of applying it to a number of different experimental units