DSCI 100 FINAL EXAM STUDY GUIDE
different types of data questions - Answers - descriptive, exploratory, predictive,
inferential, causal, and mechanistic
descriptive question - Answers - Question that asks about summarized characteristics
of a data set without interpretation (i.e., report a fact)
ex: How many people live in each province and territory in Canada
exploratory question - Answers - A question that asks if there are patterns, trends, or
relationships within a single data set. Often used to propose hypotheses for future study
ex: Does political party voting change with indicators of wealth in a set of data collected
on 2000 people living in Canada
predictive question - Answers - A question that asks about predicting measurements or
labels for individuals (people or things). The focus is on what things predict some
outcome, but not what causes the outcome.
ex: What political party will someone vote for in the next Canadian election
inferential question - Answers - A question that looks for patterns, trends, or
relationships in a single data set and also asks for quantification of how applicable these
findings are to the wider population.
ex: Does political party voting change with indicators of wealth for all people living in
Canada
causal question - Answers - A question that asks about whether changing one factor will
lead to a change in another factor, on average, in the wider population
ex: Does wealth leading to voting for a certain political party in Canadian elections
mechanistic question - Answers - A question that asks about the underlying mechanism
of the observed patterns, trends, or relationships (i.e., how does it happen)
Summarization - Answers - computing and reporting aggregated values pertaining to a
data set; most often used to answer descriptive questions and help with answering
exploratory questions
, visualization - Answers - plotting data graphically; typically used to answer descriptive
and exploratory questions (can help with all questions)
classification - Answers - predicting a categorical class (sometimes called a label) for an
observation given its other variables (sometimes called features); used to answer
predictive questions
regression - Answers - predicting a quantitative value for a new observation; used to
answer predictive questions
clustering - Answers - finding previously unknown/unlabeled sub groups in a data set;
often used to answer exploratory questions
estimation - Answers - taking measurements for a small number of items from a
population and making a good guess for the average or proportion for the population;
used to answer inferential questions
tabular data - Answers - Data organized in rows and columns.
data frame - Answers - Table-like structure for storing data in R; consist of variables,
observations, and values
1. Each element itself must either be a vector or a list.
2. Each element (vector or list) must have the same length.
observations - Answers - rows; individual objects for which we collect data; all of the
measurements for a given entity
variables - Answers - columns; these are the characteristics/number/quantity that can
be measured
comma separated values (.csv) - Answers - A file format in which a comma is placed
between each data value in the file; loaded using read_csv
function - Answers - special word in R that takes instructions (arguments) and does
something
tidyverse - Answers - a collection of open source R packages that "share an underlying
design philosophy, grammar, and data structures" of tidy data
comments - Answers - using the hash symbol (#)
accessing documentation - Answers - ? symbol; provides an easy way to pull up the
documentation for most functions quickly
path - Answers - where files live on your computer
different types of data questions - Answers - descriptive, exploratory, predictive,
inferential, causal, and mechanistic
descriptive question - Answers - Question that asks about summarized characteristics
of a data set without interpretation (i.e., report a fact)
ex: How many people live in each province and territory in Canada
exploratory question - Answers - A question that asks if there are patterns, trends, or
relationships within a single data set. Often used to propose hypotheses for future study
ex: Does political party voting change with indicators of wealth in a set of data collected
on 2000 people living in Canada
predictive question - Answers - A question that asks about predicting measurements or
labels for individuals (people or things). The focus is on what things predict some
outcome, but not what causes the outcome.
ex: What political party will someone vote for in the next Canadian election
inferential question - Answers - A question that looks for patterns, trends, or
relationships in a single data set and also asks for quantification of how applicable these
findings are to the wider population.
ex: Does political party voting change with indicators of wealth for all people living in
Canada
causal question - Answers - A question that asks about whether changing one factor will
lead to a change in another factor, on average, in the wider population
ex: Does wealth leading to voting for a certain political party in Canadian elections
mechanistic question - Answers - A question that asks about the underlying mechanism
of the observed patterns, trends, or relationships (i.e., how does it happen)
Summarization - Answers - computing and reporting aggregated values pertaining to a
data set; most often used to answer descriptive questions and help with answering
exploratory questions
, visualization - Answers - plotting data graphically; typically used to answer descriptive
and exploratory questions (can help with all questions)
classification - Answers - predicting a categorical class (sometimes called a label) for an
observation given its other variables (sometimes called features); used to answer
predictive questions
regression - Answers - predicting a quantitative value for a new observation; used to
answer predictive questions
clustering - Answers - finding previously unknown/unlabeled sub groups in a data set;
often used to answer exploratory questions
estimation - Answers - taking measurements for a small number of items from a
population and making a good guess for the average or proportion for the population;
used to answer inferential questions
tabular data - Answers - Data organized in rows and columns.
data frame - Answers - Table-like structure for storing data in R; consist of variables,
observations, and values
1. Each element itself must either be a vector or a list.
2. Each element (vector or list) must have the same length.
observations - Answers - rows; individual objects for which we collect data; all of the
measurements for a given entity
variables - Answers - columns; these are the characteristics/number/quantity that can
be measured
comma separated values (.csv) - Answers - A file format in which a comma is placed
between each data value in the file; loaded using read_csv
function - Answers - special word in R that takes instructions (arguments) and does
something
tidyverse - Answers - a collection of open source R packages that "share an underlying
design philosophy, grammar, and data structures" of tidy data
comments - Answers - using the hash symbol (#)
accessing documentation - Answers - ? symbol; provides an easy way to pull up the
documentation for most functions quickly
path - Answers - where files live on your computer
