Study Vocabulary

Question 1

Confounding variable

Answer 1

• Problem in observational studies
• Confounding variable: a variable other than variables we are investigating that varies across treatments/groups
  • Ex., gender

Question 2

Census

Answer 2

• A census is the procedure of systematically acquiring and recording information about the members of a given population
• Generates a parameter

Question 3

Parameter

Answer 3

A characteristic that describes a population (e.g. the population mean, the population standard deviation, etc.).

Question 4

Statistic

Answer 4

A characteristic that describes a sample (e.g. a sample mean, a sample standard deviation, etc.)

• Anything that describes a sample has sampling error

Question 5

Sampling error

Answer 5

Sampling error is inevitable but somewhat predicable and can be accounted for

Sampling error: the difference between a statistic and the parameter that it estimates (ex., the actual mean of the Gettysburg address vs. what I got)

Question 6

Unit

Answer 6

• 1 individual in the sample
• The unit is what receives the treatment

Question 7

Replication

Answer 7

Replication: using more than one individual/unit in a treatment group

• NOT repeated measures

Question 8

Placebo

Answer 8

Placebo: a non-active treatment

Question 9

Selection bias/coverage bias

Answer 9

• Selection bias/coverage bias: a form of selection bias that occurs when some groups in the target population are left out (undercoverage)
• Ex., sample survey of households will miss homeless, inmates, etc.

Question 10

Nonresponse bias

Answer 10

Nonresponse: a selected individual refuses or cannot be contacted

Question 11

Response bias

Answer 11

Response bias: influence of the behaviour of respondent or interviewer