# Week 6 Study Notes

GGR 270 â Lecture 6 â October 20, 2010

Sampling

îAim of inferential stats is to generalize about characteristics of larger population

îSo, need a process to obtain a sample

îSampling can be spatial or non-spatial

îTherefore, an essential skill for any geographer to have

Why Sample?

îNecessary is cases o extremely large populations

îEfficient and cost-effective way of understanding the population

îHighly detailed information can be obtained easily

îAllows for follow-up activity or repetition

Sampling Error

îIf a sample is representative of the population then it will accurately reflect the

characteristics of the population, without bias

îElement of randomness must be introduces to preserve the representative sample

îCan never eliminate bias, only minimize it

îReducing bias means reducing error

îPrecision and accuracy help categorize sources of error

Sampling Designs

îDifferent number of sampling designs:

www.notesolution.com

## Document Summary

Ggr 270 lecture 6 october 20, 2010. aim of inferential stats is to generalize about characteristics of larger population. so, need a process to obtain a sample. Therefore, an essential skill for any geographer to have. necessary is cases o extremely large populations. efficient and cost-effective way of understanding the population. highly detailed information can be obtained easily. If a sample is representative of the population then it will accurately reflect the characteristics of the population, without bias. element of randomness must be introduces to preserve the representative sample. can never eliminate bias, only minimize it. precision and accuracy help categorize sources of error. different number of sampling designs: www. notesolution. com: simple random, systematic sampling, stratified. can also have a series of spatial sampling designs: use cartesian coordinates, simple, stratified random, transect. sample statistics will change or vary for each random sample selected.