Define population - answer✔all cases (text/people)
Define sample - answer✔a smaller subgroup (of that population)
Define statistic - answer✔fact about the sample ex.) their average age of 42
Define parameter - answer✔(numerical) fact about the population (whats average, whats
typical about those groups of people)
What are descriptive statistics - answer✔Conduct simple descriptions of the characteristics of a
sample (sex, typical age, level in college, number of Facebook friends- take people/messages
and describe them)
What are inferential statistics - answer✔Make statements about the characteristics of the
population
What is random sampling - answer✔-Equal chance of selection (being chosen for study in your
group)
What is non-random sampling - answer✔the samples are gathered in a process that does not
give all the individuals in the population equal chances of being selected.
What are the sub-types of random sampling - answer✔1. Simple Random
-Select at random
-number table, digit dialing, or generator (websites and tools to help you)-
http://www.randomizer.org/form.htm
2. Systematic
-Select every __X__th person (ex. every 10th person) ex.) sometimes can be determined by the
features of your list. if you are doing a study on the population of kalamazoo, and you have a
lot of "s" last names, instead of simple random, it would be best to use systematic because you
would get the correct portion of "s" last names, etc
3. Stratified
-Select at random for known proportions (make sure you have demographic match. instead of
using the whole class randomly, separate men + women and sample the same amount from
each group)
4. Cluster
-Randomly select clustered, then individuals within
What are the sub-types of non-random sampling - answer✔Convenience
-Readily available (showing up at shopping malls, big product fairs, getting people to take a
survey// university researchers = college students)
2. Quota
-Readily available into known population proportions (attitude research about WMU,
important spread of freshman > seniors from campus)
3. Purposive
-Some seem more fit for the research (gonna need to target, ex.) older adults political attitudes
75+, go to a retirement community)
4. Snowball
-Referrals from initials informants (good in dealing with rare characteristics, ex.) find couples
who had happy divorce and could co-parents well. they probably know other couples in the
same boat. bird of a feather flock together, we hang around others with same characteristics.
you find a few, they find a few)
5. Consecutive (census)
-All accessible participants are chosen
Why should you use random sampling - answer✔1. Less bias
2. More generalizable (closer to population averages)
3. More statical options (for analyzing)
Why should you use non-random sampling - answer✔When to use Non-Random Sampling
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