Studied by 0 peopleWhat is in columns
categories
What is in rows
individual observations
What are in lines
Cases
What is numerical continuos data
Data that has no gaps (can’t have 1/2 of a person)
What is numerical discrete data
Data that has gaps (ex. money. $34.54)
What is regular categorical data
Data that has categories with an order (ex. candy types)
What is Categorical ordinal data
Categories with an order (ratings of a movie in terms of sucks, good, great)
What are associated variables
When two variables show some connection with one another
What are independent variables
When variables have no evident connection to one antoher
What variable does the explanatory variable affect
the response variable
What is positive association
When both variables move in the same direction
What is negative association
When the variables move in opposite directions
Do graphs show causation or association
association
What are the two types of study that exist?
Observational and Experimental
What are the three principles of experimental design?
Control, randomize, replicate
What needs to exist for something to be an experimental study
A type of treatment
What is another word for an explanatory variable?
Factors
What is a blocking variable
Uncontrollable inherent variables necessary to categorize
What is blocking
Blocking is putting blocking variables into groups and randomizing that which goes into those groups
What is a population
The entire group of interest, all possible members
What is a sample
a subset of the population
What is anecdotal evidence
evidence that consists of anectodes
Should we use anecdotal evidence?
No
What is a census
A census is a sample that consists of the entire population.
Exploratory analysis
When you examine a small part of a whole
Bias
Systematic distortion of sample data that tends to favor one type of result over another
What is non-response
When only a small fraction of the randomly sampled group choose to respond to a survey, the sample may no longer be representative of the population
Voluntary response sample
Occurs when the sample consists of people who volunteer to respond because they have strong opinions. This sample will not be representative of the population
Convenience sample
Individuals who are easily accessible are more likely to be included in the sample
What is a prospective study
collects data as the event in question unfolds
retrospective study
collects data as the event in question is over
What is a simple random sample
Everyone has an equal chance of being selected
Stratified Sample
groups of common characteristics (strata) and a random sample is taken from each stratum
Cluster sample
Not homogenous sample. Each cluster is representative of varied populations and a SRS is taken from each cluster
Multistage sample
SRS of initial clusters 2) Make strata from the data from the first SRS and then take another SRS
Systematic sample
Taking a random sample of every k-th subject
What do histograms show
data density
How do you interpret a histogram
See where data is concentrated, its groups, and the frequency of each group
Relative frequency histogram
Histogram with relative frequency (frequency/# of total data values=proportions)
What is modality
peaks in data
The population mean
The mean of not just the sample but of all the population
standard deviation formula
square root of the variance
Note
Flashcard