topic 6 : fieldwork

accurate

data that is as close as possible to the true value

reliable

being able to be repeated and getting a similar result every time

qualitative

data that involves word, pictures etc.

quantitative

data that involves numbers - e.g measurements of something

representative

sample should be typical of the whole population/area

subjective

something that is based on someone/s opinion

precise

related to the smallest scale of division on the equipment used

valid

when something is right for its intended purpose

quality of life

the standard of health, comfort and happiness experienced by an individual or group

river fieldwork location

Tillingbourne

rural fieldwork location

Brockham

method of measuring width of river

1. using tape measure to measure the width from one back to the other

2. hold it 5cm above the water surface

method of measuring depth of river

1. measure the width with tape measure

2. divide width by 4 to collect 5 samples using systematic sampling

3. measure the depth at each sample point using the ruler

method of measuring the velocity of river

1. measure 3m parallel in the middle of the channel with tape measure

2. drop cork 50cm upstream

3. start stopwatch when cork reaches the start of the tape measure

4. stop stopwatch when cork reaches 3m

5. repeat steps 1-4 two more times to find a mean

how did you measure width accurately

• 5cm above surface of water (+reliable)

• measured perpendicular to the flow of water

• kept tape measure tight

how did you make measuring width more precise

measured in m and cm instead of inches

limitations of the method of measuing width

• human error when reading measurements and keep tape measure straight

• external factors such as wind may affect the tape measure

• only collected data on one day - if collected after heavy rain, the width will be different

how did you measure depth accurately

• placed ruler parallel to the flow of water to prevent pillow waves

• used systematic sampling to sensure a good spread of data (+representative)

• not pushing ruler into the sediment

how did you make measuring depth more precise

measured depth in m and cm instead of inches

limitations of the method of measuring depth

• human error when reading measurements and holding equipment

• external factors such as rain may affect the depth of the river

how did you measure velocity accurately

• repeated 3 times to find the mean and check for anomalies (+reliable and representative)

• dropped cork 50cm upstream to able it to reach terminal velocity

• stayed out of cork’s way to not disrupt the flow

how did you make measuring velocity more reliable

• same person using stopwatch to reduce the impact of human error

limitations of the method of measuring velocity

• human error when reading measurements and starting and stopping stopwatch

• external factors such as wind may affect the speed of the cork

• cork could get stuck on vegetation of the bank

• only measured in the middle of the channel - not representative

method of assessing environmental quality

1. used systematic sampling to pick out five sites

2. score of 0-5 for six categories for every site

why is EQA a valid method

we can measure the living environment, which is a domaind of the IMD

positives of method of EQA

• scale of 0-5 increases accuracy as less vague measure

• systematic sampling is simple and time efficient

negatives of method of EQA

subjective to your opinion so not reliable

why is service tally a valid method

can access the number and types of services in the area → look at what the income and barriers to services are

why is questionnaire a valid method

can measure people’s opinions on education, employment and health, which are domains of the IMD

positives of questionnaire

subjective and representative

negatives of questionnaire

duriing the day, people are at work so less representative

systematic sampling

equal intervals between each point

positives of systematic sampling

• simple and easy to follow method

• shows change over space/time well

negatives of systematic sampling

• slight bias choosing simple intervals

• can give inaccessible/unsafe fieldwork locations

• may miss smaller patterns in between sample points

random sampling

every point has an equal chance of being picked

positives of random sampling

• no bias

• works well in similar (homogeneous) areas so no patterns in data missed

negatives of random sampling

• clustering of results → not representative in non similar (homogeneous) areas

• can give inaccessible/unsafe fieldwork locations

stratified sampling

divide into different areas and take a proportional number of measurements in each area

positives of stratified sampling

• valid data from accessible locations

• can be combined with systematic + random

negatives of stratified sampling

• bias when defining areas or locations

• can be more time-consuming to set up

why is river Tillingbourne a good location for your fieldwork

• it’s close to A25 so accessible and more time efficient to travel between sites

• it has a small drainage basin → safe to study

• only 19km long so change in the river can be seen over a short distance

why is Brockham a good location for your fieldwork

• it’s protected in the green belt so it’s suitable for a rural study

• it has a high quality of life

• accessible and time efficient - near our centre