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? AdvantagesDisadvantages

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? AdvantagesDisadvantages

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? AdvantagesDisadvantages

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