Fieldwork Flashcards
What sort of data would fit a bar graph?
Categoric/discontinuous data
What are the advantages of a bipolar survery
It is easy to compare
It is easy to understand
No skills are needed to carry out the survey
Does not require much equipment
What are the disadvantages of a bipolar survery
Very subjective
Based on opinions rather than facts
What are four different sampling techniques?
Random
Stratified
Systematic
Chance
What are the advantages of random sampling?
It can be used with large sample populations
It avoids bias
What are the disadvantages of random sampling?
Can lead to poor representation of the overall parent population or area if they are large
This is because the random numbers generated may miss parts out
What are the advantages of systematic sampling?
It is more straightforward than random sampling
A good coverage of the study area can be more easily achieved than using random sampling
What are the disadvantages of systematic sampling?
It is more biased, as not all members or points have an equal chance of being selected
It may therefore lead to over or under representation of a particular pattern
What are the advantages of stratified sampling?
If there are distinctive sub-groups within the overall population, it can generate results which are more representative of the whole population
It is very flexible
What are the disadvantages of stratified sampling?
The proportions of the sub-sets must be known and be accurate if it is to work properly
It can be hard to stratify questionnaire data collection
What is systematic sampling?
Involves choosing samples in a regular or systematic way for example every five minutes, every second groyne on a beach or every eighth person
What is random sampling?
Each member of the total population has an equal chance of being selected, meaning there is no subjectivity.
Deciding on your random sample can involve the use of random numbers tables or a spreadsheet set up to produce a random number to decide on the sample that is taken
What is bias?
When data is biased, we mean that the sample is not representative of the entire population.
For example, drawing conclusions for the entire population of the school based on just ten students
What is stratified sampling?
Involves a strategy for collecting data to help collect appropriate data.
For example collecting data at three sites from each stage of a river, collecting data from particular sites in a town
What is primary data?
Data you have collected yourself for example a traffic count or environmental survey
What is secondary data?
Data collected by someone else.
It could be data officially published such as rainfall records, census data, OS maps, historical data - old maps and photographs
What is quantitative data?
Data that records quantities such as numbers, sizes or frequencies
What is qualitative data?
Data that records subjective qualities such as opinions, attitudes and beliefs
What is sampling?
Sampling is the process of collecting data from sites or people. Obviously it would take too much time to collect data from a whole population or area
Therefore, sampling involves gathering data from a small part of the whole area or population.
This data is then used to give an indication of what the whole picture is like
What are the advantages of a bar graph?
Very quick and easy to draw.
The different heights of the bars make them easy to understand and make comparisons from
What are the disadvantages of a bar graph?
Can be difficult to read accurately (especially if the scale is large)
Data can be over-simplified.
Can only be used for discrete
What are the advantages of line graphs?
They are quick and easy to plot
Simple to read
Multiple sets of data can be shown using different coloured lines-easy to compare
What are the disadvantages of line graphs?
Often used incorrectly when a bar chart is more appropriate
Can only be used for continuous sets of data
What are the advantages of pie charts?
They are visually effective as it is easy to compare relative proportions of each segment
