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Page 1 3. Research Methods and Analysis C.Variables, Sampling, Hypothesis, Reliability and Validity. Page 2 3. Research Methods and Analysis C.Variables, Sampling, Hypothesis, Reliability and Validity. CHOOSING A SAMPLE: Sample is a part of larger population, representative of that population and chosen as a cross section of larger group Stages of sampling: 1) Identifying target population 2) Obtaining/producing a sampling frame (source of data) eg census, electoral register 3) Sample should have same proportion of people having relevant characteristics 4) Generalize the result Types of sampling A. PROBABILITY SAMPLING 1. Random sampling: Each unit has equal chance of being chosen (less costly and time consuming) 2. Systematic Sampling: A random starting point but next members are chosen on a fixed interval. Say, every 10 th or 20 th item to be selected. Both techniques rely on law of averages that eventually representative sample will be formed. 3. Stratified Random sampling: division of sample frames into groups to ensure sample is representative. Division is based on variable which researcher wants to control. B. NON- PROBABILITY SAMPLING 1. Quota Sampling: quota is filled for particular category and till then no responses will be collected. It is quicker and cheaper with no need to produce to sampling frame. Everybody doesn’t have chance to get selected. Difficult to fill quotas of minority. 2. Multistage sampling: samples from sample when population is large. Ex -opinion polls 3. Snowballing sampling: involves using of personal contacts of one sample entity to bring in others. Ex criminals bringing their friends. Specific and used when other techniques cant be used. 4. Volunteer sampling Non-representative sampling: 5. Convenience sampling – easily accessible and available. 6. Purposive sampling- Deliberately selected sample on the basis of certain variables. Eg: Sample for study of domestic violence from areas where incidents are higher in frequency. Page 3 3. Research Methods and Analysis C.Variables, Sampling, Hypothesis, Reliability and Validity. CHOOSING A SAMPLE: Sample is a part of larger population, representative of that population and chosen as a cross section of larger group Stages of sampling: 1) Identifying target population 2) Obtaining/producing a sampling frame (source of data) eg census, electoral register 3) Sample should have same proportion of people having relevant characteristics 4) Generalize the result Types of sampling A. PROBABILITY SAMPLING 1. Random sampling: Each unit has equal chance of being chosen (less costly and time consuming) 2. Systematic Sampling: A random starting point but next members are chosen on a fixed interval. Say, every 10 th or 20 th item to be selected. Both techniques rely on law of averages that eventually representative sample will be formed. 3. Stratified Random sampling: division of sample frames into groups to ensure sample is representative. Division is based on variable which researcher wants to control. B. NON- PROBABILITY SAMPLING 1. Quota Sampling: quota is filled for particular category and till then no responses will be collected. It is quicker and cheaper with no need to produce to sampling frame. Everybody doesn’t have chance to get selected. Difficult to fill quotas of minority. 2. Multistage sampling: samples from sample when population is large. Ex -opinion polls 3. Snowballing sampling: involves using of personal contacts of one sample entity to bring in others. Ex criminals bringing their friends. Specific and used when other techniques cant be used. 4. Volunteer sampling Non-representative sampling: 5. Convenience sampling – easily accessible and available. 6. Purposive sampling- Deliberately selected sample on the basis of certain variables. Eg: Sample for study of domestic violence from areas where incidents are higher in frequency. ADVANTAGES of Sampling: 1. Saves time and money 2. Ease of supervision as smaller size 3. Increases the accuracy of study (as proper focus) 4. A more detailed study can be conducted with the small amount of resources DISADVANTAGES: 1. Selection of proper size of sample is a difficult job, sample may not be truly representative. 2. Improper selection of sampling technique may affect the whole process 3. Faulty of biased selection will lead to inaccurate results 4. Validity is not as accurate as in census method Karl Popper: Researcher should try to falsify their theories by looking at untypical examples. Herbert Blumer: Study best informed members of social groups rather than cross section of a group Applications- NFHS, ASER Page 4 3. Research Methods and Analysis C.Variables, Sampling, Hypothesis, Reliability and Validity. CHOOSING A SAMPLE: Sample is a part of larger population, representative of that population and chosen as a cross section of larger group Stages of sampling: 1) Identifying target population 2) Obtaining/producing a sampling frame (source of data) eg census, electoral register 3) Sample should have same proportion of people having relevant characteristics 4) Generalize the result Types of sampling A. PROBABILITY SAMPLING 1. Random sampling: Each unit has equal chance of being chosen (less costly and time consuming) 2. Systematic Sampling: A random starting point but next members are chosen on a fixed interval. Say, every 10 th or 20 th item to be selected. Both techniques rely on law of averages that eventually representative sample will be formed. 3. Stratified Random sampling: division of sample frames into groups to ensure sample is representative. Division is based on variable which researcher wants to control. B. NON- PROBABILITY SAMPLING 1. Quota Sampling: quota is filled for particular category and till then no responses will be collected. It is quicker and cheaper with no need to produce to sampling frame. Everybody doesn’t have chance to get selected. Difficult to fill quotas of minority. 2. Multistage sampling: samples from sample when population is large. Ex -opinion polls 3. Snowballing sampling: involves using of personal contacts of one sample entity to bring in others. Ex criminals bringing their friends. Specific and used when other techniques cant be used. 4. Volunteer sampling Non-representative sampling: 5. Convenience sampling – easily accessible and available. 6. Purposive sampling- Deliberately selected sample on the basis of certain variables. Eg: Sample for study of domestic violence from areas where incidents are higher in frequency. ADVANTAGES of Sampling: 1. Saves time and money 2. Ease of supervision as smaller size 3. Increases the accuracy of study (as proper focus) 4. A more detailed study can be conducted with the small amount of resources DISADVANTAGES: 1. Selection of proper size of sample is a difficult job, sample may not be truly representative. 2. Improper selection of sampling technique may affect the whole process 3. Faulty of biased selection will lead to inaccurate results 4. Validity is not as accurate as in census method Karl Popper: Researcher should try to falsify their theories by looking at untypical examples. Herbert Blumer: Study best informed members of social groups rather than cross section of a group Applications- NFHS, ASER Reliability - if other researchers using the same method on same material produce the same results - if reliability can be established results can be generalized. - Generally speaking, quantitative methods are more reliable than qualitative method. Validity A valid statement gives true measurement/description and explanation of what it claims to measure. It is accurate reflection of social reality. Data can be reliable without being valid. Alan Bryman outlines four types of validity 1) Measurement validity/ Construct validity: Whether a measure that is employed really measures what it claims. Eg If IQ tests really measure intelligence 2) Internal validity: If one thing is said to cause another, this explanation will be internally valid, if causal relationship is true. Ex Pierre Bourdieu- Different cultural settings produce different educational achievements. 3) External validity: If study can be generalized to situations other than study itself. 4) Ecological validity: How accurately a research mirrors natural setting or real experience. Lab experiments may lack ecological validity. Validation by respondents (of what they actually meant) overcome problems of validity Practicality: less time consuming and less personal commitments Ethics: researcher will choose topics where informed consent and confidentiality are possible Page 5 3. Research Methods and Analysis C.Variables, Sampling, Hypothesis, Reliability and Validity. CHOOSING A SAMPLE: Sample is a part of larger population, representative of that population and chosen as a cross section of larger group Stages of sampling: 1) Identifying target population 2) Obtaining/producing a sampling frame (source of data) eg census, electoral register 3) Sample should have same proportion of people having relevant characteristics 4) Generalize the result Types of sampling A. PROBABILITY SAMPLING 1. Random sampling: Each unit has equal chance of being chosen (less costly and time consuming) 2. Systematic Sampling: A random starting point but next members are chosen on a fixed interval. Say, every 10 th or 20 th item to be selected. Both techniques rely on law of averages that eventually representative sample will be formed. 3. Stratified Random sampling: division of sample frames into groups to ensure sample is representative. Division is based on variable which researcher wants to control. B. NON- PROBABILITY SAMPLING 1. Quota Sampling: quota is filled for particular category and till then no responses will be collected. It is quicker and cheaper with no need to produce to sampling frame. Everybody doesn’t have chance to get selected. Difficult to fill quotas of minority. 2. Multistage sampling: samples from sample when population is large. Ex -opinion polls 3. Snowballing sampling: involves using of personal contacts of one sample entity to bring in others. Ex criminals bringing their friends. Specific and used when other techniques cant be used. 4. Volunteer sampling Non-representative sampling: 5. Convenience sampling – easily accessible and available. 6. Purposive sampling- Deliberately selected sample on the basis of certain variables. Eg: Sample for study of domestic violence from areas where incidents are higher in frequency. ADVANTAGES of Sampling: 1. Saves time and money 2. Ease of supervision as smaller size 3. Increases the accuracy of study (as proper focus) 4. A more detailed study can be conducted with the small amount of resources DISADVANTAGES: 1. Selection of proper size of sample is a difficult job, sample may not be truly representative. 2. Improper selection of sampling technique may affect the whole process 3. Faulty of biased selection will lead to inaccurate results 4. Validity is not as accurate as in census method Karl Popper: Researcher should try to falsify their theories by looking at untypical examples. Herbert Blumer: Study best informed members of social groups rather than cross section of a group Applications- NFHS, ASER Reliability - if other researchers using the same method on same material produce the same results - if reliability can be established results can be generalized. - Generally speaking, quantitative methods are more reliable than qualitative method. Validity A valid statement gives true measurement/description and explanation of what it claims to measure. It is accurate reflection of social reality. Data can be reliable without being valid. Alan Bryman outlines four types of validity 1) Measurement validity/ Construct validity: Whether a measure that is employed really measures what it claims. Eg If IQ tests really measure intelligence 2) Internal validity: If one thing is said to cause another, this explanation will be internally valid, if causal relationship is true. Ex Pierre Bourdieu- Different cultural settings produce different educational achievements. 3) External validity: If study can be generalized to situations other than study itself. 4) Ecological validity: How accurately a research mirrors natural setting or real experience. Lab experiments may lack ecological validity. Validation by respondents (of what they actually meant) overcome problems of validity Practicality: less time consuming and less personal commitments Ethics: researcher will choose topics where informed consent and confidentiality are possible Concepts Concepts are mental constructs or logical abstractions through which social scientists make sense of social reality. They are basically tools with which we think ,criticize, argue and explain. They serve as medium of communication among researchers. Variables Variables are specific characteristics or attributes of the more general concepts, or more specifically the attributes of events, objects and things that are observed and controlled by the researcher. They are empirical properties which take up one value or another. Earl R. Babbie- Variable is a logical set of attributes. Use- Variables help formulate hypothesis. In any social experiment , the researcher needs to identify the variables and then establish which of them are dependent and which are independent. Durkheim study of suicide-used multivariate or variable analysis.He studied the effect if independent variables like religion, gender and marital status on dependent variable viz suicide. Types: 1.Dependent and Independent Dependent Variable: The variable that depends on other factors that are measured. These variables are expected to change as a result of an experimental manipulation of the independent variable or variables. It is the presumed effect. Independent Variable: The variable that is stable and unaffected by the other variables you are trying to measure. It refers to the condition of an experiment that is systematically manipulated by the investigator. It is the presumed cause. 2.Qualitative and Quantitative Qualitative- variables which take non-numerical value Example- Gender, Religion Quantitative-variables that take up a numerical value Example-Age, Income 3.Continuous and discreet variables Discreet variables have a definite value. Continuous Variables can’t be expressed as a particular value. Example: Studying in which class will elicit a number whereas theRead More
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