All people in sampling frame are divided into groups or categories called strata. Within each group, a simple random sample or systematic sample is selected. I have decided to do a simple random sample. Example of stratified sampling:

If I want to ensure that a sample of 10 students from a group of 100 contains both male and female students in same proportions as in the full population, first divide that population into male and female. In this example, there are 54 male students and 46 females. To work out the number of males and females in the sample i will need to do the following calculations: No. of males in sample = (10/100) x 54 = 5.4

No. of females in sample = (10/100) x 46 = 4.6
I obviously can't have.4 of a person or .6 of a person in my sample, and so have to "round" the numbers. Therefore i would choose 5 males and 5 females in the sample. I will then use the random sampling technique to get my sample. I will put the females and males in seperate groups, and number them in order. I will then use the random number generator on my calculator and which ever number comes up multiply it by the size of the population and then i will use the corresponding person from the group. I will do this until i have the amount of each that i had worked out earlier using my stratified sampling method.

...ANSWER:
Sampling is that part of statistical practice concerned with the selection of an unbiased or random subset of individual observations within a population of individuals intended to yield some knowledge about the population of concern, especially for making predictions based on the statistical inference (Ader, Mellenberg & Hand: 2008). There are quite a number of sampling methods that can be employed in research and these include simple random...

...Please write down four factors which affect sampling error and for each factor, write down the effect of sampling error (i.e., if a factor is up, then what happens to the sampling error)
8. Please write down four factors to decide sample size and for each factor, write down the effect of sample size (i.e., if a factor is up, then what happens to the sample size)
9. Please write down when the systematic sampling is better than...

...Sampling
School of Nursing
The Hong Kong Polytechnic University
Sept., 16, 05; 6:30p.m. Y302
2014/9/27
1
Outline
Introduction
Select a Random Sample
Types of Sampling
• Systematic Sampling
• StratifiedSampling
• Cluster Sampling
Power Analysis
Type I and Type II Errors
Determine Sample Size – Examples
2014/9/27
2
Introduction
Sample
In statistics we always assume that a...

...Sampling Procedures
There are many sampling procedures that have been developed to make sure that a sample really represents the target population.
Simple Random Sampling
In simple random sampling, every individual in the target population has an equal chance of being part of the sample. This requires two steps:
1. Obtain a complete list of the population.
2. Randomly select individuals from that list for the sample.
In a...

...SAMPLING TECHINIQUE
PROBABILITY SAMPLING
Having chosen a suitable sampling frame and established the actual sample size required, you need to select the most appropriate sampling technique to obtain a representative sample. The basic principle of probability sampling is that elements are randomly selected in a population. This ensures that bias is avoided in the identification of the elements. It is an efficient method...

...Types of Sampling
In applications:
Probability Sampling: Simple Random Sampling, Stratified Random Sampling, Multi-Stage Sampling
* What is each and how is it done?
* How do we decide which to use?
* How do we analyze the results differently depending on the type of sampling?
Non-probability Sampling: Why don't we use non-probability sampling schemes?...

...Concept and basics of probability sampling methods
One of the most important issues in researches is selecting an appropriate sample. Among sampling methods, probability sample are of much importance since most statistical tests fit on to this type of sampling method. Representativeness and generalize-ability will be achieved well with probable samples from a population, although the matter of low feasibility of a probable sampling...

...Audit Sampling Using Statistical Methods Presented By: Abhishek Agrawal
AUDIT SAMPLING
• Application of an audit procedure to less than 100% of the items in a population
– Account balance – Class of transactions
• Examination “on a test basis” • Key: Sample is intended to be representative of the population.
APIPA 2009
2
SAMPLING RISK
• Possibility that the sample is NOT representative of the population • As a result, auditor will...