Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

A LEVEL MATHS > 1 Data Collection and LDS > Flashcards

1 Data Collection and LDS Flashcards

1
Q

What is a population?

A

A collection of all of the items we are interested in.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

What is a sample?

A

A subset of items chosen from a population.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

What is a sampling unit?

A

Each individual item in a sample.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

What is a sampling frame?

A

A list containing all sampling units, often numbered or individually named.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

What is a census?

A

Observing and measuring information from every member of a population.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

Advantages of census

A

Should give completely accurate result

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

Disadvantages of census

A

Time consuming and expensive, can’t be used when testing involves destruction, large volume of data that is hard to process

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

Advantages of sample (compared to census)

A

Less expensive, less time consuming and less data to process

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

Disadvantages of sample (compared to census)

A

Data may not be accurate, sample may not be large enough to represent small sub-groups of population

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

How is a simple random sample carried out?

A

Using X as a sampling frame. Assign each sampling unit a number from 1 to N. Use a random number generator to select ‘n’ unique numbers. Choose the items corresponding to the numbers to form your sample.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

What is a simple random sample?

A

A sample where every item in the sample has an equal chance of being selected.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

Advantages of simple random sampling

A

Bias free, easy and cheap for small populations and samples, each sampling unit has equal chance of selection.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

Disadvantages of simple random sampling

A

not suitable for big populations, sample may not be accurate for whole population, sampling frame needed.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

What is a systematic sample?

A

A sample where the required elements are chosen at regular intervals from an ordered list. (first item chosen at random)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

How is a systematic sample carried out?

A

Using X as a sampling frame. Assign each item a number from 1 to N. Randomly select the first item using a random number generator to select the first item between 1 and K and select every kth item to form sample. (k = population size / sample size)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

Advantages of systematic sampling

A

Simple and quick to use, suitable for large samples and populations.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

Disadvantages of systematic sampling

A

Can introduce bias if sampling frame is small and not random as patterns can be picked up in the data, sampling frame needed

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

What is a stratified sample?

A

A sample which is proportional to the number of items in each stratum/group

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

How is a stratified sample carried out?

A

Calculate proportion of each group required in sample. Within each group, assign each sampling unit a number. Use a random number generator to select amount of ‘unique’ numbers required. Choose the items corresponding to the numbers to form your sample.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

Advantages of stratified sample

A

Accurately reflects population structure, guarantees proportional representation of groups within population.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

Disadvantages of stratified sample

A

Sampling frame needed and population must be clearly classified into distinct strata, selection within each stratum suffers from same disadvantages as simple random sampling.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

What is quota sampling?

A

A sample chosen to reflect the proportion of characteristics of the whole population. Quotas in each group try to reflect the group’s proportion in whole population.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

How is a quota sample carried out?

A

Population is divided into groups according to characteristic. Create each quota (same proportion of sample as proportion of population). Select the sampling units until quotas are full. Once quota is full, ignore subsequent sampling units that also match that characteristic.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

Advantages of quota sample

A

Allows a small sample to still be representative of population, no sampling frame required, relatively quick, easy and inexpensive

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q

Disadvantages of quota sample

A

Non-random sapling can introduce bias, population must be divided into groups which may be costly or inaccurate, can depend on knowledge of researcher

26
Q

What is opportunity sampling?

A

Sample taken from people who are available at time of study that meet criteria.

27
Q

How is opportunity sampling carried out?

A

Select first ‘n’ amount of people who fit criteria to form sample

28
Q

Advantages of opportunity sampling

A

Easy to carry out, inexpensive

29
Q

Disadvantages of opportunity sampling

A

Unlikely to provide a representative sample, highly dependent on knowledge of individual researcher

30
Q

What is qualitative data?

A

Non-numerical data e.g. colour

31
Q

What is quantitative data?

A

Numerical values

32
Q

What is discrete data?

A

Data that only takes specific values e.g. shoe sizes, number of children

33
Q

What is continuous data?

A

Data that can take any decimal value e.g. height, weight

34
Q

Why may class intervals be inaccurate?

A

Use of the midpoint of class intervals assumes values are evenly distributed within the interval, which may not be accurate.

35
Q

Name the 5 UK weather stations

A

Leuchars, Leeming, Heathrow, Hurn, Camborne

36
Q

Name the 3 International weather stations

A

Jacksonville, Beijing, Perth

37
Q

Leuchars general info

A

Most northern in UK, lowest average temperatures

38
Q

Leeming general info

A

Second most northern in UK, sheltered location leads to dry, almost semi-arid, climate

39
Q

Heathrow general info

A

Far from city so temperatures not raised by ‘urban heat island’ effect, below average rainfall for Britain, relatively hot summer temperatures due to southerly latitude and close proximity to continental Europe

40
Q

Hurn general info

A

Close to Southern coast, rainfall well below national average

41
Q

Camborne general info

A

Most southern in UK, mildest and sunniest UK climate due to southern location and warm water from Gulf stream. Sea moderates extreme temperatures in summer and winter but extreme rainfall is not uncommon

42
Q

Beijing general info

A

Humid and continental climate. Lower latitude than UK, humid summers due to East Asian monsoon, cold and windy but dry winters due to Siberian anticyclone

43
Q

Jacksonville general info

A

Humid and subtropical climate. Low lying so winters are mild and sunny. Summers are hot, very humid and prone to thunderstorms.

44
Q

Perth general info

A

Hot summer and Mediterranean climate, winters cool and wet, summers are hot dry and sunny. Some summer rainfall.

45
Q

What happened October 16 1987?

A

A large storm hit the UK.

46
Q

What is wind direction?

A

The direction the wind is blowing FROM

47
Q

What is the meaning of tr?

A

Trace meaning values of rainfall less than 0.05mm

48
Q

What value should be used if tr is being used in a calculation?

A

0.025

49
Q

What is total rainfall?

A

Total precipitation that falls in a 24 hour period measured in mm

50
Q

What is maximum gust?

A

Highest instantaneous windspeed measured in knots.

51
Q

What are the units for windspeed?

A

Knots and also a corresponding description given on Beaufort Scale.

52
Q

What does n/a mean?

A

Data not available and so should be discounted from sample.

53
Q

What is total sunshine measured in?

A

Nearest 1/10th of an hour

54
Q

What is humidity?

A

The % of air saturation with water vapour.

55
Q

What is mean pressure measured in?

A

Hectopascals

56
Q

What is mean visibility?

A

How far can be seen into horizon during daylight hours measured in decametres. 1Dm = 10m

57
Q

What is mean cloud cover measured in?

A

Oktas which means the number of 1/8ths of the sky is covered from 0 to 8. There are 9 possible options (important in probability qs)

58
Q

How many possible options on a compass?

A

16

59
Q

What happened October 2015 in Perth?

A

Perth had warmest October since records began

60
Q

What happened October 1987 and 2015 in Beijing?

A

Beijing significantly colder in October relative to May-September

A LEVEL MATHS (1 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions