Quiz 1 Flashcards
Survet definition
uncontrolled collection of available. You can only use what we have
experiment defintion
controlled generation and collection of data
population definition
collection of all subjects or objects of interest
sample definition
a subset of the population, selected by some members of the given population,
sampling definition
a way of generating a sample by selecting some members of the given population
What does the sample represent?
the population or close to it
definition of statistic
a numerical measure obtained from a sample used to categorize the sample.
definition of parameter
a numerical measure that characterizes the entire population
In most cases, can we calculate the parameter
no
definition of simple random sample
random sample in which each group member has the
same probability of being selected.
How is simple random sample usually obtained
by using random numbers
definition of random numbers (n)
a collection of numbers that are each likely to occurr with probability 1/n for each number
What are the 2 properities of random numbers
Each digit 0, 1, 2, . . . , 9 is equally likely to occur.
(2) The value of any particular digit is independent of the value of any other digit
selected.
definition of bias
anything that produces systematic errors in data
definition of sampling bais
systematc error to a nonrandom nature of the sample
what is a measurement bias
systmatic error that happern in collecting data. equipment and people mare erroes
recall or memory bias
response are affected by responders memory
which one is better: short term or long term memory
short term
What is a randomized clinical trial
a type of research design used for comparing different
treatments, in which patients are assigned to a specific treatment by some random
mechanism. T
What happens before starting a clinical trial?
you have to write a proposal that describes in detail the design of proposed reasearch
What are the 2 experimental groups that clinical trials have?
teatment and control
What is the treatment group
drug or intervention of interest
What is the control group?
another drug, procedure, or placebo
What is the purpose of blinding and randomization
it helps minimize bias
What is Block randomization?
in clinical trials comparing two treatments
(treatments A and B). A block size of 2n is determined in advance, where for every 2n
patients entering the study, n patients are randomly assigned to treatment A and the
remaining n patients are assigned to treatment B.
single blind study
the patient does not know the treatment and group assignment, but the physician does.
double blind study
neither patient or physican knows treatment or group assignment
unblinded study
both patient and the doctor knowns the treatment and group assignments
