UBC DSCI 100 Midterm Review 2025 Questions with Correct Answers|New Version with complete solutions

UBC DSCI 100 Midterm Review
inferential question - Correct Answer-looks for patterns, trends, or relationships in a
single data set AND asks for qualification of how applicable findings are to a wider
population

causal question - Correct Answer-asks abut whether or not changing one factor will lead
to a change in another factor, on average, in a wider population

mechanistic question - Correct Answer-asks about the underlying mechanism of the
observed patterns, trends, or relationships

descriptive question - Correct Answer-asks about summarized characteristics of a data
set without interpretation (reports facts)

exploratory question - Correct Answer-asks if there are patterns, trends, or relationships
within a data set (used for hypotheses for future studies)

predictive question - Correct Answer-asks about predicting measurements or labels for
individuals and focuses on what things predict a specific outcome but not what causes
the outcome

read_csv("filepath") - Correct Answer-reads comma-separated values files

filter(tbl, condition) - Correct Answer-obtains a subset of rows with desired values from a
data frame

select(tbl, columns_as_arguments) - Correct Answer-extracts specific columns from a
data frame

arrange(tbl, by=desc/asc(columns_as_arguments)) - Correct Answer-orders the rows of
a data frame by values of a specific column

slice(tbl, row_range) - Correct Answer-keeps only the rows in a specific range

mutate(tbl, column_name = ...) - Correct Answer-modifies (use existing column name)
or creates (use a new column name) a column in a data set

ggplot(tbl, mapping) - Correct Answer-creates a plot for data in a tidy data set

geom_bar() - Correct Answer-bar graph

, geom_point() - Correct Answer-scatterplot

read_csv("filepath", skip = n) - Correct Answer-tells R how many lines to skip before it
should start reading in the data (n = number of lines skipped)

read_tsv("filepath") - Correct Answer-reads tab-separated values files

read_delim("filepath", delim = "", col_names = FALSE) - Correct Answer-the generic
version of read_csv and read_tsv that can read either format

download.file(url, "filepath") - Correct Answer-downloads data from a url into the
specified filepath

read_excel("filepath") - Correct Answer-reads data stored in Excel files

read_csv2("filepath") - Correct Answer-reads semicolon separated files

dbConnect(RSQLite::SQLite(), "filepath") - Correct Answer-opens a communication
channel that R can use to send SQL commands to the database

dbListTables(tbl) - Correct Answer-lists all of the tables in a databse

tbl(dataset, "table") - Correct Answer-allows us to work with data stored in databases as
if they were regular data frames

show_query(tbl(dataset, "table")) - Correct Answer-looks at the SQL commands sent to
the database from the tbl command

collect(database_table) - Correct Answer-convert a database into a tibble

min(column) - Correct Answer-returns the minimum value in a numeric column

write_csv(tbl, "filepath") - Correct Answer-converts data into a csv file

read_html("url") - Correct Answer-tells R which page to scrape by providing the
website's URL, directly downloading the source code for the page at the specified URL

tidy data - Correct Answer-a data format that is suitable for analysis

data frame - Correct Answer-a table-like structure for storing observations, variable, and
their values in R

variable - Correct Answer-a characteristic, number, or quantity that can be measured

observation - Correct Answer-all of the measurements for a given entity