QTM 100 EXAM 1 STUDY GUIDE
descriptive statistics - Answers - charts, graphs, describe the data but doesn't
manipulate
inferential statistics - Answers - conclusion/prediction from the data, hypothesis testing
variable - Answers - characteristic, attribute that you are interested in
data - Answers - values, measurements, observations of variables
random variables - Answers - determined by chance
ex. tossing a die and seeing how many times you get a four
data set - Answers - collection of data
data matrix - Answers - each column represents a variable and each row represents a
particular case or observation
categorical - Answers - qualitative data, answer is words
numerical - Answers - quantitative data, answer is numbers
discrete - Answers - whole numbers
ex. 3 children
continuous - Answers - on a scale, fractions and decimals
ex. 3.4 hours
nominal - Answers - categorical, no order
ex. male/female
ordinal - Answers - categorical, with order
ex. good/better/best
interval - Answers - numerical, differences defined, ratios not defined, no inherent 0
ex. temperature, IQ
ratio - Answers - numerical, differences and ratios are defined, inherent 0, fractions
make sense
ex. weight, height, age
summary statistics - Answers - a single number summarizing a large amount of data
spurious correlation - Answers - no reason for the relationship
, ex. number of people who drowned in pool and films Nicholas Cage starred in
anecdotal evidence - Answers - data collected in a haphazard fashion or non-scientific
fashion, may be true or may only represent extraordinary cases, worst way to collect
data
before collecting data... - Answers - clearly lay out the question being investigated
carefully target the population being studied
population - Answers - all the subjects being studied
census - Answers - data from every member of the population
sample - Answers - Subcollection of members selected from a population, represents
subset of the cases
population parameter - Answers - data describing the population
sample statistics - Answers - data describing a sample
observational study - Answers - just observe, cannot establish causal relationship
experimental study - Answers - treat and observe, may be able to establish causation
randomized experimental study - Answers - subjects are randomly places in
control/treatment groups, best way to establish casual relationship
confounding variable - Answers - associated with both variables, unaccounted for,
related to both
prospective study - Answers - present, continuous, identifies individuals and collects
information as events unfold
retrospective study - Answers - look at past data and past records, collects data after
events have taken place
simple random sample - Answers - best way to sample, every subject has an equally
likely chance of being selected, no bias
systematic sampling - Answers - look at the kth person in the list
stratified sampling - Answers - divide population into categories (strata) and have
samples from each
cluster (intact) - Answers - many clusters, randomly choose clusters to use in study and
use entire cluster, INTACT
descriptive statistics - Answers - charts, graphs, describe the data but doesn't
manipulate
inferential statistics - Answers - conclusion/prediction from the data, hypothesis testing
variable - Answers - characteristic, attribute that you are interested in
data - Answers - values, measurements, observations of variables
random variables - Answers - determined by chance
ex. tossing a die and seeing how many times you get a four
data set - Answers - collection of data
data matrix - Answers - each column represents a variable and each row represents a
particular case or observation
categorical - Answers - qualitative data, answer is words
numerical - Answers - quantitative data, answer is numbers
discrete - Answers - whole numbers
ex. 3 children
continuous - Answers - on a scale, fractions and decimals
ex. 3.4 hours
nominal - Answers - categorical, no order
ex. male/female
ordinal - Answers - categorical, with order
ex. good/better/best
interval - Answers - numerical, differences defined, ratios not defined, no inherent 0
ex. temperature, IQ
ratio - Answers - numerical, differences and ratios are defined, inherent 0, fractions
make sense
ex. weight, height, age
summary statistics - Answers - a single number summarizing a large amount of data
spurious correlation - Answers - no reason for the relationship
, ex. number of people who drowned in pool and films Nicholas Cage starred in
anecdotal evidence - Answers - data collected in a haphazard fashion or non-scientific
fashion, may be true or may only represent extraordinary cases, worst way to collect
data
before collecting data... - Answers - clearly lay out the question being investigated
carefully target the population being studied
population - Answers - all the subjects being studied
census - Answers - data from every member of the population
sample - Answers - Subcollection of members selected from a population, represents
subset of the cases
population parameter - Answers - data describing the population
sample statistics - Answers - data describing a sample
observational study - Answers - just observe, cannot establish causal relationship
experimental study - Answers - treat and observe, may be able to establish causation
randomized experimental study - Answers - subjects are randomly places in
control/treatment groups, best way to establish casual relationship
confounding variable - Answers - associated with both variables, unaccounted for,
related to both
prospective study - Answers - present, continuous, identifies individuals and collects
information as events unfold
retrospective study - Answers - look at past data and past records, collects data after
events have taken place
simple random sample - Answers - best way to sample, every subject has an equally
likely chance of being selected, no bias
systematic sampling - Answers - look at the kth person in the list
stratified sampling - Answers - divide population into categories (strata) and have
samples from each
cluster (intact) - Answers - many clusters, randomly choose clusters to use in study and
use entire cluster, INTACT
