SYG 4300 02 Social Research Methods Final Review Guide This is a broad list of concepts relevant to the final exam I encourage you to know concepts examples calculations and interpretations Sample Elements Sampling Frame Sampling Error The individual units often individual persons that comprise a sample List of all the sampling units from which the sample is drawn Sampling error is the deviation of the selected sample from the true characteristics traits behaviors qualities or figures of the entire population Sampling process error occurs because researchers draw different subjects from the same population but still the subjects have individual differences Ways to eliminate Representativeness o This solution is to eliminate the concept of sample and to test the entire population Subset of a statistical population that accurately reflects the members of the entire population Unbiased indication of what population is like Probability vs Non probability Sampling Methods Non probability sampling Probability of being chosen is unknown o o To satisfy concerns about the sample s representativeness the researcher must explicitly explain how the sample represents the population from which it was drawn o Cheaper but unable to generalize o o Convenience Sample ease of access sample is selected from elements of a population that are Potential for bias easily accessible Probability sampling o Methods for drawing a sample in which the probability of selecting population elements is known The researcher uses random sampling so that the representativeness of the sample characteristics to the known population characteristics can be statistically calculated o Random Sample each subject has a known probability of being selected o Allows application of statistical sampling theory to result to Generalize Test hypothesis Ensure representativeness and precision Systematic Random Sample From the sample frame a starting point is chosen at random and thereafter at regular intervals For example suppose you want to sample 8 houses from a street of 120 houses o o 120 8 15 so every 15th house is chosen after a random starting point between 1 and 15 If the random starting point is 11 then the houses selected are 11 26 41 56 71 86 101 and 116 Advantages Disadvantages Spreads the sample more evenly over the population o o Easier to conduct than a simple random sample o The system may interact with some hidden pattern in the population e g every third house along the street might always be the middle one of a terrace of three Stratified Random Sample A probability sample that is organized to capture known group differences among the population In the first stage elements are sorted into separate groups called strata according to the selected group characteristics In the second stage elements are randomly sampled from within strata For example you want to find out whether workers who did a lot of overtime work had higher performance scores If you had existing data suggesting that workers who had children were less likely to work overtime than those who did not have children you would divide the employee population into two groups parents and non parents You would then randomly select an equal number of people from each subgroup Advantages Cluster Sample o Captures key population characteristics in the sample o Works well for populations with a variety of attributes A random sampling plan in which the population is subdivided into groups called clusters so that there is small variability within clusters and large variability between clusters Then the required information is collected from a simple random sample of the elements within each selected group Advantages o Cheaper Disadvantages o Higher sampling error Availability Sample Convenience sample Quota Sample A nonprobability sample in which elements are drawn based on their availability to the researcher Quota sampling is a non probability sampling technique wherein the assembled sample has the same proportions of individuals as the entire population with respect to known characteristics traits or focused phenomenon o The first step in non probability quota sampling is to divide the population into exclusive subgroups o Then the researcher must identify the proportions of these subgroups in the population this same proportion will be applied in the sampling process Finally the researcher selects subjects from the various subgroups while taking into consideration the proportions noted in the previous step o The final step ensures that the sample is representative of the entire population It also allows the o researcher to study traits and characteristics that are noted for each subgroup In a study wherein the researcher likes to compare the academic performance of the different high school class levels its relationship with gender and socioeconomic status the researcher first identifies the subgroups Usually the subgroups are the characteristics or variables of the study The researcher divides the entire population into class levels intersected with gender and socioeconomic status Then he takes note of the proportions of these subgroups in the entire population and then samples each subgroup accordingly o Allows the researcher to sample a subgroup of great interest to the study o Allows researcher to observe relationships between subgroups o May not always be representative of the population o Traits may be overrepresented Advantages Disadvantages Purposive sample Snowball sample A nonprobability sample in which the researcher selects elements for a specific purpose usually because of the unique characteristics of the elements A nonprobability sample in which the researcher asks the initial elements usually people to refer to other potential elements for inclusion in the sample The process is repeated until the sample grows i e snowballs to the size desired by the researcher Normal Curve A symmetrical curve representing the normal distribution Advantages of Survey Research Versatility Efficiency Generalizability Considerations when designing survey questions Avoid jargon slang and abbreviations Avoid ambiguity confusion and vagueness o Use of indefinite words or response categories o First think seriously about what you want to measure and then consider the circumstances of respondents o Words with strong emotional connotations can color how respondents hear and answer survey Avoid emotional language questions Avoid prestige bias o Titles or positions in