The difference between the sample results and the result of a census conducted using identical procedures ? Statistical fluctuation due to chance variations Systematic Errors ? Nonsampling errors ? Unrepresentative sample results ? Not due to chance ? Due to study design or imperfections in execution ...
•Nonsamplingerrors•Unrepresentativesampleresults•Notduetochance•Duetostudydesignorimperfectionsin execution ErrorsAssociatedwithSampling •SamplingFrameError•RandomSamplingError•NonresponseError TwoMajorCategoriesofSampling •ProbabilitySampling •Known,nonzeroprobabilityforeveryelement •Nonprobability...
Systematic Error系統誤差 —nonsampling errors 測量工具不精準imperfect aspect of the research design 測量執行時的錯誤mistake in the execution of the research A sample bias exists when the results of a sample show a consistent tendency to deviate in one direction from the true value of the ...
SAMPLING METHODS PPT
Types of Non-probability Sampling Four main techniques used for a non-probability sample: Convenience Judgemental Snowball Quota Convenience Sampling It is a non-probability sampling technique used to create sample as per ease of access, readiness to be a part of the sample, availability at a give...
ChapterSamplingPPT教学课件 SAMPLING ––AcrucialstepinconvertingCTsignalstoDT,sothatwecanuseversatiledigitalcomputersorDSPstoprocessthem.Example:Digitalrecordingofsounds 第1页/共33页 Theissueofsamplingappliestospatiallyvaryingsignals 第2页/共33页 Contents ➢Theconceptofsamplingandthesamplingtheorem ➢Theprocess...
Sources of error Potential Sources of Error in Research Designs Total error Random sampling errors Response errors Non-sampling errors Non-response errors Researcher errors Interviewer errors Respondent errors School of Management www.som.surrey.ac.uk (Malhotra & Birks, 2003 p74) Non-probability ...
There are essentiality two types of sampling: probability non-probability sampling. Probability Sampling Methods Probability or random sampling gives all members of the population a known chance of being selected for inclusion in the sample and this does not depend upon previous events in the selection...
Non Non--probability samples (2): probability samples (2): • Selection of extreme cases, such as good or very poor compliers to treatment, is a powerful and rapid strategy to identify contributing factors to poor compliance • In the same way, selection of a poorly and a well...
McGraw-Hill/Irwin 15 Nonsampling Error –A bias that occurs in a research study regardless of whether a sample or census is used Population frame error Measurement error Response error Errors in gathering and recording data Overview: The Basics of Sampling Theory Understand the concept of error in...