Data collection

Question 1

Define a population

Answer 1

The whole set of data that is of interest

Question 2

Define a Sample

Answer 2

The subset of the population intended to represent the population

Question 3

Define a sampling unit

Answer 3

Each individual thing in the population that can be sampled.

Question 4

Define a sampling frame

Answer 4

sampling units in a population being individually numbered to form a list.

Question 5

what are the two types of sampling a population?

Answer 5

Census and Sample

Question 6

define a sample

Answer 6

a subset of the population that is intended to represent the whole population

Question 7

Define a census

Answer 7

An investigation of the whole population

Question 8

what are the pros and cons of a census

Answer 8

Pros:
- gives a reliable and accurate result, representing the whole population

Cons:
- very time-consuming and expensive.
- a lot of data to process
- can’t be used for testing when the process destroys the item.

Question 9

What are the pros and cons of a sample?

Answer 9

Pros:
- less costly and time-consuming
- More manageable bits of data.
- fewer people have to respond

Cons
- may not be representative of the whole sample
- sample size might not be large enough- so maybe not reliable
- might be less accurate.

Question 10

what are the types of sampling methods

Answer 10

• simple random
• systematic
• opportunity
• quota
• stratified

Question 11

What is simple random sampling? how to carry it out?

Answer 11

It can be carried out through a sampling frame being assigned numbers, then using a random number generator or a calculator to choose. (ran# x range of sampling frame)

Question 12

What is systematic sampling?

Answer 12

When a sample is chosen at particular intervals from a list.

Question 13

What is stratified sampling?

Answer 13

when the population is divided into mutually exclusive strata, and is then randomly sampled from there.

Question 14

What is quota sampling?

Answer 14

when a researcher selects sampling units that fit the characteristics of the whole population.

Question 15

What is opportunity sampling?

Answer 15

When the people that are available at the time of the study, and fit the criteria for it are used as a sampling frame.

Question 16

What are pros and cons of random sampling?

Answer 16

Pros:
- Not biased
- easy and cheap for small populations

Cons:
- a sampling frame is needed
- not suitable when the population size is too large.

Question 17

What are the pros and cons of systematic sampling?

Answer 17

Pros:
- simple and quick
- suitable for large populations

Cons:
- can introduce bias
- a sampling frame is needed

Question 18

What are pros and cons of stratified sampling?

Answer 18

Pros:
- sample accurately represents the population.
- guarantees proportional representation of the groups within a population.

Not usable if population too large
sampling frame needed

Question 19

What are the pros and cons of Quota sampling?

Answer 19

Pros:
- small sample can be representative of the population
- simple and easy, inexpensive

Cons:
- can introduce bias
- might have to split into more groups, which can add time and expense
- non-responses aren’t recorded

Question 20

What are the pros and cons of opportunity sampling?

Answer 20

Pros:
- easy
- inexpensive

Cons:
- dependant on the individual researcher
- Unlikely to provide a representative sample.

Question 21

What are the different types of data?

Answer 21

• quantitative
• qualitative
• discrete or continuous

Question 22

What is continuous data?

Answer 22

A variable can take any value in a given range. eg: 2.5, 2.1 secs.

Question 23

What is discrete data?

Answer 23

A variable can take only specific values in a given range. Eg: you cant really have 4.5 people in a family.

Question 24

What are the places in the UK that have been mentioned in the large data set?

Answer 24

Heathrow
Camborne
Hurn
Leeming
Leuchars

Question 25

What are the places internationally that have been mentioned in the large data set?

Answer 25

Jacksonville
Beijing
Perth

Question 26

what are the assumptions of the particle model?

Answer 26

• mass concentrated at a single point
• rotational forces and air resistance can be ignored

Question 27

what are some assumptions of the rod model?

Answer 27

mass concentrated along a line
no thickness
rigid

Question 28

what are the assumptions of the lamina model?

Answer 28

mass distributed as a flat surface

Question 29

What are some assumptions about the uniform body model?

Answer 29

mass concentrated at the centre of mass.

Question 30

What are some assumptions of the Light object model?

Answer 30

objects have 0 mass
tension is the same at both ends of a light string

Question 31

What are some assumptions of the inextensible string model?

Answer 31

acceleration is the same in objects connected by a taut inextensible string

Question 32

What are some assumptions of the smooth surface model?

Answer 32

no friction

Question 33

what are some assumptions of the rough surface model?

Answer 33

THere is friction present if acted on by a force

Question 34

what is an assumption of a wire

Answer 34

treated as one dimensional

Question 35

smooth and light pulley model assumptions

Answer 35

• pulley has no mass
• tension on both sides is the same along the sides of the beam

Question 36

What are some assumptions of the bead model?

Answer 36

Moves freely along a wire or string
tension is the same on either side of the bead

Question 37

what are some assumptions of the peg model

Answer 37

• dimensionless and fixed
• can be rough or smooth (question dependant)