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Homework Answers. To Worksheet X in the booklet. Data Collection Methods. Aims: To know the advantages and disadvantages of different sampling techniques and be able to apply them to the Geography IA. Recap…. - PowerPoint PPT Presentation
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Homework Answers
• To Worksheet X in the booklet
Data Collection Methods
Aims: •To know the advantages and disadvantages of different sampling techniques and be able to apply them to the Geography IA
Recap…
• We need to find out how the height of buildings (number of floors) changes as you move from the PLVI to the rural-urban fringe in HK
• What PLVI shall we use? How did you decide?• Last lesson we agreed on 3 transects through HK
(we’ll see them later)• When going along the transects how should we
select buildings to include in our sample?
Random Sampling
• In a random sample every building in the study area has an equal chance of being picked.
• So is probably not as simple as you might think• You would first need to identify each building
in the sample area, allocate it a number and then pull out the numbers at random
Random Sampling
• What are the benefits and problems of using this technique?
Advantages Disadvantages
Systematic Sampling
• Systematic sampling is when buildings are chosen at regular intervals, e.g. every 400m
• What are the benefits and problems of this option – specifically for our study?
Advantages Disadvantages
Stratified Sampling
• If you know there are important sub-groups in the sample area (e.g. CBD, inner city, inner suburbs, etc) you can select a sample that ensures each sub-group is represented fairly
• What are the benefits and problems of using this technique?
Advantages Disadvantages
Finalising our Method
• The three transects are:
Transect 1: Nathan Road
Transect 2: Chatham Road
Transect 3: Queensway
However…
• How should we select which buildings to count in our sample?
• Now let’s organise you into groups and decide which transect you will work on
• Before we finalise the details, how many buildings will we need in our sample to make it statistically reliable?
To the computer room…• What we need to decide:
– How far is it from one end of the transect to the other?
– How many intervals should you have? – Therefore, how far apart will the intervals
be? – Therefore, specifically, where will the
intervals be? – How many buildings either side of the
transect should we include in the sample? – How should we decide which buildings?
Homework
• Complete Worksheet X in the booklet by next lesson
What do the pictures mean?
I’m teaching – listen!
Try to answer questions if you can
Work in silence
You can discuss the work
Work in a group