Drawing Conclusions from Studies

Question 1

What is a null hypothesis?

Answer 1

A hypothesis suggesting there is no association to be observed, all visible correlations are caused by error (explanatory variable has no impact)

Question 2

What is the structure of a hypothesis?

Answer 2

If-then statement; If (observation unit) is changed by (statement about explanatory variable) then I expect that (statement about change in the response variable)

Question 3

What is an alternative hypothesis?

Answer 3

A hypothesis that reflects the expected change in the response variable due to the explanatory variable

Question 4

What is an experiment?

Answer 4

A study that imposes treatment or changes the state of the observational units

Question 5

What is an observational study?

Answer 5

A study using previous data or observing and recording information without imposing a treatment or changing the states of the observational units

Question 5

What is a population?

Answer 5

All observational units in a certain category

Question 5

What is a sample?

Answer 5

Some of the observational units in a population

Question 6

What is a parameter?

Answer 6

Measures of a population

Question 6

What is a statistic?

Answer 6

Measures of a sample

Question 7

What is a representative sample?

Answer 7

A sample with similar characteristics to its original population

Question 8

What is the sample size?

Answer 8

The number of observational units sampled

Question 9

What is sampling frame?

Answer 9

A list of all observational units in a population

Question 10

What causes a sample to be random and fit Simple Random Sampling (SRS)?

Answer 10

All observational units in a population have equal chance of being selected

Question 11

What is convenience sampling?

Answer 11

Data is collected from observational units the researcher has easy access to

Question 12

What is voluntary response sampling?

Answer 12

Submitting data for a study is optional (e.g., a survey that is not required)

Question 13

What is undercoverage bias?

Answer 13

Parts of a population are less sampled that others in a data collection and underrepresented

Question 14

What is non-response bias?

Answer 14

When those selected for a data collection refuse to respond and are underrepresented

Question 15

What is response bias?

Answer 15

The behavior of the observational unit or researcher causes a bias in the data (e.g., people are already biased for or against something when interviewed and those are the only people interviewed)

Question 16

What is wording bias?

Answer 16

A question written poorly enough to confuse the audience in their response

Question 17

What is a lurking variable?

Answer 17

A variable that is not the explanatory variable but is related to the response variable and might be the cause of an association between the explanatory and response variables

Question 18

What is a confounding variable?

Answer 18

A variable that explains the explanatory variable and the response variable and explains the association between them (the explanatory variable does not cause the response variable, the confounding variable does)