The process of statistical study

Question 1

Lis the 4 steps in conducting a statistical study

Answer 1

1. Determine the design of the study

• state the question to be studied
• determine the population and variables
• determine the sampling method

2. Collect the data
3. Organize the data
4. Analyze the data to answer the question

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Question 2

Identify the population of interest and the variable in this study.

“Neurologists want to study the effect of vitamin C on nerve disorders. The goal of the study is to see if taking an intravenous dose of vitamin C will reduce the amount of nerve pain reported by patients.

Answer 2

The population is ALL patients with nerve disorders.

Variables is the amount of vitamin C, amount of nerve pain.

Question 3

An ____________ observes data that already exist.

Answer 3

observational study

Question 4

An ________ generates data to help identify cause-and-effect relationships.

Answer 4

experiment

Question 5

True or False

A statistician will refer to any ‘theoretical’ data collection as an experiment.

Answer 5

True

Question 6

Which type of study would you conduct? (observational vs experiments)

‘You want to determine the average age of college students across the nation’

Answer 6

observational study

Question 7

Which type of study would you conduct? (observational vs experiments)

‘Researchers wish to determine if flu shots actually help prevent severe cases of the flu’

Answer 7

experiement study

Question 8

A ___________ sample has the same relevant characteristics as the population and does not favor one group from the population over another.

Answer 8

representative

Question 9

How do you know if a sample is representative of the population?

Answer 9

???

Question 10

‘My sample is all females in this class. Is it a representative sample?’

Answer 10

yes … keyword ALL

Question 11

Cite five sampling techniques?

Answer 11

1. simple random
2. stratified
3. cluster
4. systematic
5. !convenience

Question 12

define simple random sample

Answer 12

every sample from the population has an equal chance of being selected.

Question 13

define a stratified sample?

Answer 13

where the population is divided into subgroups called strata. The grouping variable is correlated with the measurement variable. A sample is drawn from each stratum.

Question 14

Define cluster sampling?

Answer 14

The population is divided into subgroups, called clusters. The grouping variable is not correlated with the measurement variable. A sample can be drawn from at least one of the clusters.

Question 15

Define systematic sampling?

Answer 15

selecting every nth member of the population

Question 16

Define convenience sampling and the issues with using it?

Answer 16

the sample is convenient for the researcher to select, considered bias sampling.

Note: unethical

Question 17

Identify the sampling method.

‘A pollster surveys 50 people in each of a senator’s 12 voting precincts’

Answer 17

simple sample

Question 18

Identify the sampling method.

‘The quality control department at a cereal manufacturer measures the weight of every 10th box off of the assembly line.’

Answer 18

systematic sampling

Question 19

Identify the sampling method.

‘A female student walks down the halls in her dorm asking students how much money they would spend in a food court in the dorm lobby in an effort to persuade the administration to offer such an opinion.’

Answer 19

convenience sampling (bias)

Question 20

Identify the sampling method.

‘An educator chooses 5 of the school districts in the Chicago area and asks each household in those districts how many school-age children are in the home.’

Answer 20

cluster sampling

Question 21

Identify the sampling method.

‘To determine who will win a $100,000 shopping spree at the mall, the manager draws a name out of a box of entires.’

Answer 21

simple random sampling

Question 22

Q: What is the primary difference between cluster and stratified sampling?

Answer 22

???

Question 23

Cite two observational studies?

Answer 23

cross-sectional
longitudinal

Question 24

In a ______ study, data are collected at a single point in time.

Answer 24

cross-sectional (many members)

Question 25

In a _________ study, data are gathered by following a particular group over a period of time.

Answer 25

longitudinal (few members)

Question 26

Classify the studies?

‘A group of 220 patients is followed for 15 years in order to determine the long-term health effects resulting from gastric bypass srue