Statistics and Mechanics Chapter 1 - Data Collection

Question 1

Quota sampling

Answer 1

The population is split into groups and a certain number from each group is chosen in any order.

Question 2

Stratified sampling

Answer 2

The population is split into groups and a proportional representation of the different groups is selected.

Question 3

Simple random sampling

Answer 3

Every member of the population has an equal chance of being selected.

Question 4

Opportunity sampling

Answer 4

A convenient sample is taken from any members of the population at any time.

Question 5

Systematic sampling

Answer 5

Take every nth unit

Question 6

A researcher uses simple random sampling on a list of gym members to research what times they go to the gym. What is the sampling frame?

Answer 6

The membership list.

Question 7

Pros and cons of quota sampling

Answer 7

Pros:
No sampling frame required, allows a small sample to still be representative of the population, quick, easy, inexpensive
Cons:
Potential for bias, population must be divided into groups, which can be costly or inaccurate.

Question 8

Pros and cons of stratified sampling

Answer 8

Pros:
Accurate, cost effective, prevents bias, guarantees proportional representation
Cons:
A sampling frame is needed, population must be clearly classified into distinct strata

Question 9

Pros and cons of simple random sampling

Answer 9

Pros:
Simple, quick, cheap, free of bias, each sampling unit has an equal chance of selection
Cons:
Time consuming and expensive when sample size is large, requires a sampling frame

Question 10

Pros and cons of opportunity sampling

Answer 10

Pros:
Quick and easy, does not need a sampling frame, inexpensive
Cons:
Unlikely to provide a representative sample, highly dependent on individual researcher

Question 11

Pros and cons of systematic sampling

Answer 11

Pros:
Simple and quick, suitable for large samples
Cons:
Needs a sampling frame

Question 12

What is a population?

Answer 12

The whole set of items that are of interest

Question 13

Pros and cons of a census

Answer 13

Pros:
Should give a completely accurate result
Cons:
Time consuming, expensive, hard to process large quantity of data, could destroy sampling units (eg testing every battery’s life)

Question 14

Pros and cons of a sample

Answer 14

Pros:
Less time consuming and expensive than a census, less data than a census
Cons:
Data may not be as accurate, the sample may not be large enough to give information about small sub-groups of the population

Question 15

What are sampling units?

Answer 15

The individual units of a population.

Question 16

What is a sampling frame?

Answer 16

When sampling units are individually named or numbered.

Question 17

What is quantitative data?

Answer 17

Variables or data associated with numerical obervations.

Question 18

What is qualitative data?

Answer 18

Variables or data associated with non-numerical observations.

Question 19

What is a continuous variable?

Answer 19

A variable that can take any value in a given range.

Question 20

What is a discrete variable?

Answer 20

A variable that can take only specific values in a given range.