Chapter 7 Flashcards
Population
all individuals that the research applies to
ex- study on whether CU students are happier when puppies are around, the population is all CU students
census
when you measure the entire population
sample
group of people you got from the population to be in your study
sampling frame
list of everyone in the POPULATION
this is how you get your sample
population vs sample
population is the entire group & the sample is only the part of that population you are actually measuring
Representative samples
- represent the population
- random sample of everyone in the population
- everyone has an equal chance of being in your sample
simple random
have the SAMPLING FRAME & then randomly choose how may people you want in your study
-everyone has an equal chance
-this is not randomly talking to people as they walk around campus
ex- CU students are the population, get all of the ID numbers of EVERY student & randomly pick 50 students
systematic sampling
get a SAMPLING FRAME & pick a random number and then you take the sample & divide it by the desired amount for the survey & pick every #th one
ex- the researcher started by selecting two random numbers - 4 & 7. the researcher then started on the 4th person and picks every 7 th name
Cluster Sampling
randomly choose a group and then you choose a cluster & take EVERYONE in that cluster
ex- want to study undergraduates in Colorado, choose CU, DU, Mines, & CSU as your cluster & look at ALL of those students
multistage sampling
you start out by taking a population & then take out clusters and then choose another form of sampling to get your results
ex- 7 decks pf cards & then randomly choose 3 of those decks, then use a simple random sample on those 3 decks
stratified random smaple
researchers selects particular demographic categories on purpose and then randomly selects individuals within each of the categories
ex- a group of researchers might want to be sure their sample of 1,000 Canadians includes people of South Asian descent in the same population as in canadian population. So they have two two categories (strata) in their population: South Asian Canadians and other Canadians. In a sample if 1,000 they include at least 40 members of South ASIan. It is imported that both categories are selected randomly
oversampling
we have a specific demographic we want to sample, we know there isn’t a lot so we need to oversample (over represent)
ex- in a sample of 1,000 the researchers want to make sure South Asians are represented & the researchers population is only 4% so instead of sampling only 40 they sample 100
what are all the representative samples?
simple random systematic sampling cluster sampling multistage sampling stratified random sampling oversmapling
Bias sampling
external validity isn’t vital to the study goals, researcher might be okay with a bias sample
convince sampling
sample whatever is convent to you
ex- most studies being sophomore psych students- taking a survey of people in your class