Sampling Flashcards
What are the 5 steps to a reserch project
development of a reserch question
design of study
collection of data
description/ analysis of results
interpritation of results
What is the importance of study design
its the
- method to select participants
- control experimental conditions
-collect data
What can the method of study design impact
- results and interpritation of results
- information produced,
- good reserch requires a good design
what are the two types of study designs
- examples of each
decriptive - survay
- aim: describe the characteristics of people
- uses a sample
analytic - experimental / observational
what are the two sources of errors in samples
systematic errors: bias in the method of data collection for a sample,will skew the results of the sample, increasing sample size will have no effect on the biase
random errors: random from the population which will be reduced with increased sample size, CAN be estimated with statistical models
what is a sampling frame
the list of people/objects from which the sample can be drawn from
ensure well defined population
What are three types of descriptive study designs
simple random sample
stratified random sample
cluster sample
What is a simple random sample
for a population size N draw n candidates each has the same possibility of drawn
what is a stratified random sample
groups known as stata are decided
each group can then have a simple random sample done with them
can be proportonal to population or equal from each strata
benifits: more preceise than SRS, decide results about strata
What is a cluster sample 1 + 2 stage
1 stage cluster ramples gains information about a cluster of poeple at ranom
two stage gains random objects then random objects from that random object to come up with a sample
benifits: convenient and cheap but less accurate
what is imporatnt about the analysis of the data
to ensure that anylitic methods are tailored to the design
