30 Questions
In systematic sampling, what is the main disadvantage?
Selections are not truly equal and independent
What is the main advantage of stratified random sampling?
May produce more accurate results because small groups are not missed, and large ones are not over-represented
What is a key disadvantage of cluster sampling?
Sampling estimates are subject to errors in the stratification criteria
What is the fundamental characteristic of simple random sampling?
Each sampling unit in the population has an equal chance of being selected
What is a challenge of conducting a random sample of all the trees in a forest?
Cost and difficulty in accessing widely-dispersed locations
What is a key advantage of systematic sampling?
Simple to execute in practice, because sample units are located at regular intervals and travel is straight-forward
What is a significant disadvantage of simple random sampling?
Relies on human choice, which is prejudiced by individual opinion
What is a drawback of conducting cluster sampling?
Requires developing a system consistent with the sampling unit
What is a challenge of conducting systematic sampling?
Can fare poorly if systematic patterns occur within the population
What is a key advantage of stratified random sampling over simple random sampling?
May produce more accurate results because small groups are not missed, and large ones are not over-represented
What is the definition of a population in the context of sampling?
The total set of individuals or potential observations in a defined group
What is the role of sampling in addressing difficult questions?
Determining sample size, sample selection, and result reliability
What are sampling units in the context of sampling?
The individual items in a sample, and the basic entity upon which observations are made
Why is conducting a census often not feasible?
Due to the impracticality of measuring all the individuals in a population
What are the learning outcomes of Topic 13 in GEOG 380?
To identify the similarities between non-spatial and spatial sampling, recognize different elements considered when selecting the number of samples, and apply different sampling methods
What is the definition of a sample in the context of sampling?
A subset of individuals or observations in the population
What are the difficult questions that sampling helps us answer?
How large should the sample be, how/where should the samples be chosen, and how much reliability will we have in results based on this sample
What are the different elements considered when selecting the number of samples?
Sample size, sample diversity, and result reliability
What is the definition of sampling units in the context of sampling?
The individual items in a sample, and the basic entity upon which observations are made
What is the main reason for sampling when conducting research?
To make inferences about a population without having to measure the entire population
What is one important consideration in proper sample design?
Matching the scale of the sampling units to the desired information
Which method is used for sample size determination involving the desired level of confidence, standard deviation, and tolerable error?
Formula method
What is the major issue in sample selection?
Avoiding bias
Which sampling method is often used to study populations where subjects are hard to identify or reach?
Snowball sampling
What is the difference between random sampling error and systematic sampling error?
Random sampling error results from sample result differences, while systematic error results from non-sampling factors
Which type of sampling method involves selecting sampling units based on a specific characteristic of interest?
Stratified random sampling
What is the advantage of snowball sampling?
Useful for studying hard-to-reach populations
What is the precision of the estimate of a population parameter a function of?
Variance of the population, sample size, and allowable error
Which method for sample size determination involves iterating until a reasonable sample size is reached?
Procedure method
What is a non-probability sampling method that involves selecting sampling units based on the researcher's judgment and knowledge of the population?
Judgmental sampling
Study Notes
Sampling Methods and Sample Size Determination in Geographic Research
- Sampling units must be explicitly defined and selected to match the scale of the information desired.
- The project aims to use machine learning to discover Medicine Wheels in Alberta, with the study site being the Siksika Native Reserve and over 100 locations in the Alberta Archaeological Site Inventory Records.
- One important question in proper sample design is how large the sample should be to be representative, with larger samples providing more certainty but also incurring more cost.
- Different methods for sample size determination include rules of thumb and formulas, with the precision of the estimate of a population parameter being a function of the variance of the population, the sample size, and the allowable error.
- Random sampling error is the difference between the sample result and the result of a census conducted using identical procedures, while systematic sampling error results from non-sampling factors in a study's design and execution.
- Less than perfectly representative samples can result from random sampling errors and systematic errors.
- Two methods for sample size determination include a formula involving the desired level of confidence, standard deviation of a pilot sample, and tolerable error, and a method involving the Student’s t-value, coefficient of variation, and tolerable error expressed as a percentage of the mean.
- The procedure for sample size determination involves making a reasonable guess at the sample size, looking up critical Student’s t-value, selecting values for allowable error and coefficient of variation, calculating the sample size, and iterating until a reasonable sample size is reached.
- The major issue in sample selection is to avoid bias, including under-representing or over-representing elements of the population due to inappropriate sample design.
- There are various sampling methods and designs, including non-probability methods like judgmental, quota, and snowball sampling, and probability methods like systematic, simple random, stratified random, and clustered random sampling.
- Snowball or chain-referral sampling is a non-probability sampling method often used to study populations where subjects are hard to identify or reach, such as individuals with rare diseases or homeless individuals.
- This sampling method is advantageous in practical situations but may not be suitable for well-designed sampling strategies.
Test your knowledge of sampling methods and sample size determination in geographic research with this quiz. Explore the importance of sample design, sample size determination methods, and the impact of sampling errors on research outcomes. Gain insights into various sampling methods and designs, including probability and non-probability approaches, and their application in geographic research.
Make Your Own Quizzes and Flashcards
Convert your notes into interactive study material.
Get started for free
