Week 3 Flashcards
What is Sample Study?
Trying to estimate the value of a parameter for a population
ex) How long does each individual spend on the computer per day
What is Observational Study?
Trying two understand how 2 parameters relate to one another. You cant make a conclusion on a causality because of a lurking variable
ex) How does blood pressure relate to computer time
What is Experiment Study?
The basis of the scientific method and main purpose is to determine causality. It shows causality because you use randomization
What is Bias?
Error in methodology that results in a way systematic deviation of the result away from the truth and being pulled in one direction
What is Random Error?
The results are being pulled in different direction
What are Confounding variables?
is an outside influence that changes the effect of a dependent and independent variable
What is population?
group of people, objects or events
What is Target Population?
The larger population to which results of a study will be generalized too
What is Accessible Population?
The actual population of subjects available to be chosen for a study
What is Sample?
A subgroup of the population of interest (accessible population) which allows the results of research to be generalized to the population
What is Sampling bias?
Extent that systematically misrepresentation population can be conscious or unconscious
What is Sampling Error?
Extent that sample randomly misrepresents population
What are some Sampling techniques?
- Probability Sampling
- Non probability Sampling
What are some Probability Sampling?
- Simple Random Sampling
- Systematic Sampling (every 10th person)
- Stratified Random Sampling (specify # from each category)
- Cluster Sampling (multilayer/stage)
What are some Non Probability Sampling?
- Convenience Sampling (subjects are chosen on basis of availability
- Constructive Sampling ( Recruit all folks to meet inclusion/exclusion criteria)
- Volunteers
- Quota Sampling (like stratified, but not random
_Purposive Sampling (subjects hand picked by specific criteria)
What are some considerations with Non Probability Sampling?
- must be more careful with inferences and generalizations
2. Closely examine inclusion/exclusion criteria and baseline characteristics
What are some examples of Experimental Research?
- Randomized Trial
- Clinical Trial
- Randomized Clinical Trial
- Randomized Controlled Trial
What are extraneous variable?
Any factor not related to the purpose of the study, which may affect dependent variables. Also known as nuisance variables
What happens when extraneous variables become uncontrolled?
They become confounding variables
What is the purpose of Experimental Research?
they are designed to control confounding variable
What are the 3 essential components of Experimental Research?
- Include a control/comparison group
- Independent variables are being manipulated by the experimenter
- Subjects are randomly assigned to groups
What is a random assignment?
Each subject has an equal chance of being assigned to any group and help control for extraneous variables or prognostic indicators
What should Random Assignments do?
- Should results in homogenous groups at baseline except for the IV
- Concealing allocation: Separate people
- Sealed envelopes
What are ways to incorporate Missing Data in a study?
- Per Protocol Analysis: Analyze only those who complete the study
- Intention to Treat Analysis: Analyze in the group that they were assigned too and use Imputation (estimating missing data values)
- As treated (Observe data regardless of what happens and then move them)
