statistics data collection

Question 1

population

Answer 1

the population is everyone or everything you are interested in

Question 2

census

Answer 2

if you collect data from the whole population its called a census

Question 3

sample

Answer 3

if you collect data from part of the population its called a sample

Question 4

sampling unit

Answer 4

the population broken down into sectors

Question 5

sampling frame

Answer 5

how you can get a list of the population

Question 6

simple random sampling method

Answer 6

everyone has equal chance of getting picked
this can be done many ways for example giving everyone in you population a number and then using a random number generator to randomly pick people

Question 7

pros of random sampling method

Answer 7

-no bias
-efficient and chap if population is small
-every person has equal chance

Question 8

cons of random sampling methods

Answer 8

• could be not representative of the whole group
  -not suitable for a large sample
  -need a full sampling frame

Question 9

systematic sampling method

Answer 9

randomly pick a number one then pick everyone after in a set interval

Question 10

pros to systematic sampling

Answer 10

-simple and quick
-suitable for a large population
representative of whole population

Question 11

cons to systematic sampling

Answer 11

-need sampling frame
- bias can happen if sampling frame not random

Question 12

stratified sampling method

Answer 12

split population into strata’s (groups) to insure each group is proportionally represented as the sample is split in proportional to the population

Question 13

stratified sampling pros

Answer 13

-sample reflects the proportion structure
-proportionally representative of al the groups in the population

Question 14

stratified sampling cons

Answer 14

-have to organise population into strata’s
-could suffer from all the con s of the other two as they are often used within this method

Question 15

quota sampling method

Answer 15

picking people that match your criteria only and selecting them using convenience sampling

Question 16

pros of quota sampling

Answer 16

-quick and easy

Question 17

cons of quota sampling

Answer 17

-non random sampling can introduce bias
-can be costly

Question 18

opportunity/ convenience sampling method

Answer 18

picking people in the most convenient way possible so whoever you come across

Question 19

opportunity/ convenience sampling pros

Answer 19

-quick and easy

Question 20

opportunity/ convenience sampling cons

Answer 20

-unlikely to be representative of the whole group

Question 21

quantitive

Answer 21

uses numbers

Question 22

qualitive

Answer 22

uses words

Question 23

continuous

Answer 23

is measured

Question 24

discrete

Answer 24

can be counted

Question 25

class boundaries

Answer 25

the maximum and minimum values that belong in each class

Question 26

midpoint

Answer 26

average of class boundaries

Question 27

class width

Answer 27

difference between the upper and lower class boundaries

Question 28

advantages of a census

Answer 28

completely accurate results

Question 29

disadvantages of a census

Answer 29

time consuming and expensive

Question 30

advantages of using a sample

Answer 30

less time consuming and expensive then census less data to process

Question 31

disadvantages of using a census

Answer 31

data may not be as accurate sample my exclude small group of population depending on size

Question 32

what are sampling units

Answer 32

individual units of the population