Sampling Design Essay

936 words - 4 pages

Sampling Designs
• 1. Simple random sampling (SRS) Steps:
– (1) Assign a single number to each element in the sampling frame. – (2) Use random numbers to select elements into the sample until the desired number of cases is obtained.

• The method is not very different from winning a lottery.

2. Systematic Sampling
• Steps:
– (1) Calculate the sampling interval as the ratio between population size and sample size, I = N/n. – (2) Arrange all elements in the population in an order. – (3) Select a case in the first interval randomly. – (4) Select every ith case from this point.

2. Systematic Sampling (continued) I
1st element, randomly chosen





– Systematic ...view middle of the document...

• If this assumption is not true, => the sample has more variability than a sample obtained by SRS, resulting in inefficiency. • In general, we can only lose efficiency with cluster sampling.

Sources of Variability in a Sample Statistic
• 1. Population Variability All elements in a population are inherently variant. • 2. Random Selection Precisely because elements in the population have different values on a variable, random selection is meaningful and necessary.

Decomposing Variability
• 1. ANOVA: Analysis of Variance
Total variation = between-group variation + within-group variation.

• Internal homogeneity => external heterogeneity => between-group variance is large (e.g., gender and height). • Internal heterogeneity => external homogeneity => between-group variance is small (e.g., gender and GPA).

Effects of Stratification
• Stratification reduces sampling variation. • Total variation - between-strata variation = within-strata variation. • The more heterogeneous are the strata externally (or equivalently, the more homogeneous internally), the greater the gain in precision arising from stratification. • Example of gun control law and region.

Design Effect
• The ratio of the variance of the estimator
based on the complex design to the variance of the estimator based on simple random sampling of the same size. • D2(z) = V(z)/V(z0) • For stratified samples, D2 ≤ 1. That is, stratified samples cannot be less efficient than simple random samples. D2 = 1 if strata do not differ from each other.

Effects of Clustering
• Clustering increases sampling variation. • For a cluster sample, the Design Effect (D2) ≥ 1. That is, cluster samples cannot be more efficient than simple random samples. D2 = 1 if clusters do not differ from each other. • Example of cluster sampling of individuals based on state of residence.

Cluster sampling vs. Stratification.
• Since strata are all represented in the sample, it is advantageous if they are internally homogeneous...

Other Papers Like Sampling Design

Surevying Phonebooks Essay

1334 words - 6 pages compiled from the additional clusters, stacked with the initial clusters and then the descriptive statistics were calculated. Sampling Design and Theory There are a number of sampling methods that could be used to sample the data. Such sampling techniques are (but not limited to); Simple Random Sampling, Stratified Random Sampling, Systematic Sampling and Cluster Sampling. A simple random sample is obtained by choosing elementary units in

Quantitative Methods in Management Essay

1303 words - 6 pages specification - What questions to ask? In what order? 6. Scale specification - How will preferences be rated? 7. Sampling design specification - What is the total population? What sample size is necessary for this population? What sampling method to use?- examples: Probability Sampling:- (cluster sampling, stratified sampling, simple random sampling, multistage sampling, systematic sampling) & Nonprobability sampling:- (Convenience Sampling,Judgement

Methods Assignment

1207 words - 5 pages 3. METHODOLOGY 3.1 Introduction This Chapter is devoted for the methodological aspects of the study. This includes description of the study area, study design, target population, sample size, sampling methods, instrumentation, data collection procedures and methods of data analyses. 3.2 Study area The study area is Accra in the Greater Region of Ghana and covers stakeholders in the banc assurance business including the Banks, Micro-Finance

Shs972 – Assignment 1

3171 words - 13 pages ) which is also referred to in chapter 7 of the Regulations 2011. Question 2: Part A Dusts in the workplace may have negative effects on the health of workers if inhaled. These dusts range in size from 1μm to 100μm in diameter (Tillman, 2007). ISO 7708:1995 details the three size fractions of dust for health related sampling which are: • Inhalable fractions: Inhalable fractions have an aerodynamic diameter of less than 100μm. Inhalable dust

Data and Biases

1533 words - 7 pages efficacy of a product. A prevailing method of analyzing numerical data is known as statistical analysis and the activity associated with assessing and explaining data in order to make predictions is referred to as inferential statistics. Knowledgeable consumers understand the value of discerning the veracity of data interpretations, forecasts and recommendations by recognizing sources of bias such as sampling procedures, or

Qualitative Research

1639 words - 7 pages groups, and participant observation Design • Rigid design • Controlled & experimental • Emergent design Focus • Prediction • Outcomes • Generalisability • Rich “thick” description • Similarities & contrasts • Process & context Nature of data analysis • Statistical • Non-statistical Sampling • Relatively large samples using often random sampling • Small samples using purposive, convenient or snaw ball sampling technique. METHODS OF

Business Research Methods, Part I

873 words - 4 pages the outputs of the university, such as jobs that graduates may receive upon completion of a degree or the amount of students who apply for enrollment. In order for University of Phoenix to provide advanced, quality education to millions of Americans busy with work and family, its researchers must define a sample design to select people from a designated population. Sampling saves time and money, and if used properly the sample accuracy and

Business Process Reengineering

566 words - 3 pages Agenda • Why is data required for BPR? Understand the types of data relevant to the process Learn how to identify which data to collect Understand sampling and other data collection techniques Why to collect data? • Data is used in process analysis − To quantify the problem at hand (“it takes too long for getting a passport” vs. “issuance of the passport takes 41 days on average”) − To identify which sub process is the least

Analysis and Implications of Practice: Quantitative Research

1021 words - 5 pages the practice. MacKusick and Minick (2010) conducted semi-structured interviews with those RN’s who left clinical nursing. The questions used in the interview process were open-ended which give you a better understanding as to why they made their decision. Given the topic, the design used gave most information about the subject’s importance; it’s relevance to practice, and left information for further study. Methods/Sampling The authors of

Data Collection

871 words - 4 pages measures what it intended to measure. Another measurement tool is reliability, which measures consistency. Reliability refers to the extent to which the research measure is a consistent and dependable indicator of the investigation. If the measuring technique provides the same results once the measurement is repeated the accuracy of the measurement is high (Suresh, 2011) Selection biases are induced by sampling design. The sample group

Research Summary

690 words - 3 pages behavior associated with the six categories causative of morbidity and mortality among youth (Kann). These leading causes can be summarized as the behavior contributing to unintentional injuries, alcohol and other drug use, use of tobacco, sexual behavior leading to STIs and unintended pregnancy, unhealthy dietary behavior and physical inactivity. Stratified sampling The recent sampling assumes two- stage cluster sample design in the year 2013. The

Related Essays

Sampling Design Plan Essay

1626 words - 7 pages Alternative Ways to Animal Testing In the world today, science has seen its better days. Scientific methods developed and invented scientists have been used to demonstrate and explain almost everything in the world. Researchers studying biological issues have produced reports informing about the issues that surround us. For example, in tests that require human spacemen have been conducted using non-human animals for biological animal

Sample Design Essay

409 words - 2 pages 3.1 Research Design 3.2 Sample Design 3.2.1 Target population It would be costly and timely for us to target the whole marketing industry hence we decided to target on specific segment group of UTAR undergraduate students in Sungai Long, Selangor. We study the behavioral respond view of UTAR undergraduate’s students on their perceived on quality, value and satisfaction toward the intention to recommend products or services. According by

Sampling Probability Essay

3292 words - 14 pages widely dispersed geographically and that the time and the cost of collecting data becomes very large. It produces large errors. Random sampling may produce the most non random looking results. Systematic Sampling Advantages It is simple to design and convenient to adopt. It is easier to use than simple random sampling It is easy to determine sampling distribution Less expensive than random sampling. The time and work involved in sampling by

Inquiring Minds Want To Know Essay

1047 words - 5 pages Case Assignment 2 Liberty University BUSI 600 Abstract This paper defines Penton Media’s sampling plan and research design for their study on if their reader service cards are still successful in getting buyer’s attentions. There are five questions that develop the sampling plan and Penton Media’s answers to these questions are described in this paper along with the strengths and weaknesses of their decisions. Their research design is