Data collection

Question 1

Qualitative

Answer 1

Data that usually given in words not numbers to describe something

Question 2

Quantitative

Answer 2

Data that is given using numbers which counts or measures something

Question 3

Discrete

Answer 3

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

Question 4

Continuous

Answer 4

A variable that can take any value in a given range

Question 5

class boundaries

Answer 5

They tell the maximum and minimum values that belong in each class

Question 6

midpoint

Answer 6

the average of the class boundaries

Question 7

class width

Answer 7

the difference between the upper and lower class boundaries

Question 8

population

Answer 8

A whole set of the things that you are interested in

Question 9

sample

Answer 9

A subset of the population which is used to collect the data from

Question 10

sampling frame

Answer 10

a list of all members of the population
sample unit is one thing within sampling frame

Question 11

population parameter

Answer 11

a numerical value which describes a characteristic of the population

Question 12

sample statistic

Answer 12

a value computed using data from the sample

Question 13

Census Definition

Answer 13

Collects data about all the members of a population

Question 14

Census Adv

Answer 14

Gives fully accurate results

Question 15

Census Disadv

Answer 15

Time consuming and expensive to carry out, can destroy or use up all the members of a population when they are consumable

Question 16

Sampling Def

Answer 16

collects data from a subset of the population, the size of sample can affect the validity of any conclusion drawn

Question 17

Sampling Adv

Answer 17

quicker and cheaper, less data needed to be analysed

Question 18

Sampling DisAdv

Answer 18

might not represent the population accurately, could introduce bias

Question 19

Simple Random Def

Answer 19

A sample where every possible sample of size n has an equal chance of being selected

Question 20

Simple Random Adv

Answer 20

Easy for small samples
Random Sample
Free of bias

Question 21

Simple Random DisAdv

Answer 21

Difficult for large samples
Sampling frame

Question 22

Systematic Sampling Def

Answer 22

Where every nth person is picked from an ordered sampling frame

Question 23

Systematic Sampling Adv

Answer 23

Random Sample
Quick / Easy for small samples

Question 24

Systematic Sampling DisAdv

Answer 24

Sampling frame needed
If list is not random, the sample may not b random

Question 25

Stratified Sampling Def

Answer 25

The population is divided into disjoint groups(called strata) and then a random sample is taken form each group(stratum) - The proportion of a stratum that is sampled is equal to the proportion of the population that belong to that stratum

Question 26

Stratified sampling Adv

Answer 26

Sample accurately reflects the population structure, Guarantee proportional representation of groups within a population

Question 27

Stratified Sampling DisAdv

Answer 27

Population must be clearly classified into distinct strata, selection within each stratum suffers from the same disadvantages as simple sampling

Question 28

Quota Sample Def

Answer 28

Where the population is split into strata (groups) and a sample size is chosen for each group that is proportional to the group size. These people are then selected on a first come first served basis. Once you reach your quota, you stop.

Question 29

Opportunity sampling

Answer 29

consists of taking the sample from people who are available at the time the study is carried out and who fit the criteria you are looking for

Question 29

Opportunity Sampling Adv

Answer 29

Easy to carry put, Inexpensive

Question 30

Quota Sample Adv

Answer 30

Do not need sampling frame Quick easy + cheap Reflects population Structure

Question 31

Opportunity sampling Disadv

Question 32

Quota Sample DisAdv

Answer 32

Not random sample People may refuse Interviewer bias Not always possible to split population into distinct groups