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types of sampling
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Sampling methodsGroup Name:
Wailay
Group members:
Malik Arsalan ALI khan 034
M.Saad
M.Shujahat 058
Khawar Abbas 056
Types of probability sampling
• Probability sampling
• Non probability sampling
Probability sampling
• A type of sampling in which every element of population has equal chance of selection
Types of probability sampling
• Simple random sampling
• Systematic random sampling
• Stratified random sampling
• Cluster sampling
Simple random sampling
• A method of probability sampling in which every unit has known and equal chance of being selected.
Method of simple random sampling
• With replacement
• Without replacement
Systematic random sampling
• A method of probability sampling in which the defined population is ordered and sample is selected by using skip interval.
Method of systematic random sampling
• Obtain the ordered list of units
• Determine number of units in list and desired sample size
• Determine the start point randomly
• Select sample by skip interval.
Stratified random sampling
• A method of sampling in which a population is divided into different subgroups and samples are drawn randomly.
Cluster sampling
• A method of sampling in which sampling units are selected in groups rather than individually.
Non probability sampling
• A method of sampling in which every element has unknown and unequal chance of selection.
Convenience sampling
• convenience sampling is a type of non probability sampling which involves the sample being drawn from that part of the population which is close to hand
Judgmental sampling
• the researcher chooses the sample based on who they think would be appropriate for the study. This is used primarily when there is a limited number of people that have expertise in the area being researched.
Quota sampling
• A quota is established (say 65% women) and researchers are free to choose any respondent they wish as long as the quota is met.
Snow ball sampling
• he first respondent refers a friend. The friend also refers a friend, and so on. Such samples are biased because they give people with more social connections an unknown but higher chance of selection
Sample design
• A methodological plan to obtain a sample from a given population.
Steps
• Types of population
• Sampling frame
• Sampling units
• Sampling methods
• Sampling size parameters
• Budgetary constraints
Characteristics of ideal sample design
• Must produce representative sample
• Must result in less sampling error
• Must be feasible in context of available funds.
• Should have results which can be applied to whole population.
• Should be able to prevent systematic bias.
Types of errors in sampling
• Sampling error
• Non sampling error
Sampling error
• The difference between a sample statistic and population parameters.
How to minimize sampling error sampling error
• Increasing sample size
• stratification
Non sampling error
• That does not occur due to sampling.
Reasons
• Improper division of sampling units
• Poor response of responses
• Bias
• Intentional bias
• Unintentional bias