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argument

the inputs to a function; the expressions for each argument follow the function name

average

a representation of the center, or 'typical' value in a set of numbers, calculated as the sum of those numbers divided by the number of values.

bar chart

a display of categorical data that uses bars positioned over category values; each bar’s height reflects the count or percentage of data values in that category

bias

prejudice in favor of or against one outcome, person, or group compared with another, usually in a way considered to be unfair.

bin

a range that values from a dataset can belong to; there is one bar in a histogram per bin

Boolean

a type of data with two values: true and false

box plot

the box plot (a.k.a. box-and whisker-plot) is a way of displaying a distribution of data based on the five-number summary: minimum, first quartile, median, third quartile, and maximum

categorical data

data whose values are qualities that are not subject to the laws of arithmetic

comments

messages in the code, generally ignored by the computer, to help people interacting with the code understand what it is doing

conditional

a code expression made of questions and answers

confounding variable

an unaccounted-for variable that influences the relationship between variables being analyzed

contract

a statement of the name, domain, and range of a function

contract error

errors where the code makes sense, but uses a function with the wrong number or type of arguments

correlation

a single number somewhere between -1 and +1 that reports the direction and strength of the linear relationship between two quantitative variables (also known as the r-value)

data row

a structured piece of data in a dataset that typically reports all the information gathered about a given individual

data science

the science of collecting, organizing, and drawing general conclusions from data, with the help of computers

data type

a way of classifying values, such as: Number, String, Image, Boolean, or any user-defined data structure

dataset

a collection of related information that is composed of separate elements, but can be manipulated as a unit by a computer

define

to associate a descriptive name with a value

definitions area

the left-most text box in the Editor where definitions for values and functions are written

direction

the relationship between two quantitative variables: either they increase/decrease together or one may increase while the other decreases

distribution

a description of the number of times or relative probabilities that different quantities occur in a sample

domain

the type or set of inputs that a function expects

editor

software in which code can be written and evaluated

error message

information from the computer about errors in code

example

shows the use of a function on specific inputs and the computation the function should perform on those inputs

explanatory variable

any variable that could impact the "response variable", generally plotted on the x-axis of a scatter plot

form

the shape of a relationship between two quantitative variables: whether the two variables together vary linearly or in some other way

frequency

how often a particular value appears in a dataset

function

a relation from a set of inputs to a set of possible outputs, where each input is related to exactly one output

function definition

code that names a function, lists its variables, and states the expression to compute when the function is used

grouped sample

a non-random subset of individuals chosen from a larger set, where the individuals belong to a specific group

header

the titles of each column of a table, usually shown at the top

histogram

a display of quantitative data that uses vertical bars positioned over bins (sub-intervals); each bar’s height reflects the count or percentage of data values in that bin.

identifier column

a column of unique values which identify all the individual rows (e.g. - student IDs, SSNs, etc)

interactions area

the right-most text box in the Editor, where expressions are entered to be evaluated

interquartile range

(IQR) is one possible measure of spread, based on dividing a dataset into four parts. The values that divide each part are called the first quartile (Q1), the median, and third quartile (Q3). IQR is calculated as Q3 minus Q1.

line of best fit

summarizes the relationship (if linear) between two quantitative variables

linear regression

a type of analysis that models the relationship between two quantitative variables. The result is known as a regression line, or line of best fit.

linear relationship

sequences that change at a constant rate, or points forming a straight line on a graph

maximum

the largest value in a dataset

mean

a representation of the center, or 'typical' value in a set of numbers, calculated as the sum of those numbers divided by the number of values.

median

the middle element of a quantitative dataset

method

a function that is only associated with an instance of a data type, which consumes inputs and produces an output based on that instance

minimum

the smallest value in a dataset

mode

the most commonly appearing categorical or quantitative value or values in a dataset

name

how we refer to a function or value defined in a language (examples: +, *, star, circle)

null hypothesis

the hypothesis that there is no significant difference between specified populations, any observed difference being due to sampling or experimental error.

operator

a symbol that manipulates two Numbers and produces a result

outlier

observations whose values are very different from the other observations in the same data set, perhaps due to experimental error. Outliers can also be indicative of data belonging to a different population from the rest of the established samples.

percentage

a ratio showing the parts per hundred

pie chart

a display that uses areas of a circular pie’s slices to show percentages in each category

piecewise function

a function that computes different expressions based on its input

predictor function

a function which, given a value from one dataset, makes an educated guess at a related value in a different dataset

programming language

a set of rules for writing code that a computer can evaluate

purpose statement

a concise, detailed description of what a function does with its inputs

quantitative data

number values for which arithmetic makes sense

quartile

each of four equal groups into which a population can be divided according to the distribution of values of a particular variable.

r

a number between −1 and 1 that measures the direction and strength of a linear relationship between two quantitative variables (also known as correlation value)

random sample

a subset of individuals chosen from a larger set, such that each individual has the same probability of being chosen

range

the type or set of outputs that a function produces

range of a dataset

the distance between minimum and maximum values

ratio

the relative sizes of two or more values

response variable

the variable in a relationship that is presumed to be affected by the explanatory variable, generally plotted on the y-axis of a scatter plot

sample

a set of individuals or objects collected or selected from a statistical population by a defined procedure

sample size

the number of participants or observations included in a study

scatter plot

a display of the relationship between two quantitative variables, graphing each explanatory value on the x axis and the accompanying response on the y axis

selection bias

the non-random selection of individuals, groups, or data

shape

The aspect of a dataset - visible in a histogram or box plot - that describes which values are more or less common.

skew

lack of balance in a dataset’s shape, arising from more values that are unusually low or high. Such values tend to trail off, rather than be separated by a gap (as with outliers).

skewed left

A distribution is skewed left if there are a few values that are fairly low compared to the others. A histogram of data that is skewed left will have a clump of taller bars on the right, with smaller ones trailing off to the left, like the shape of the toes on a left foot.

skewed right

A distribution is skewed right if there are a few values that are fairly high compared to the bulk of data values. A histogram of data that is skewed right will have a clump of taller bars on the left, with smaller ones trailing off to the right, like the shape of the toes on a right foot.

slope

the steepness of a straight line on a graph

spread

the extent to which values in a dataset vary, either from one another or from the center

standard deviation

a number that measures spread of a data set using the typical distance of values from their mean

statistical inference

using information from a sample to draw conclusions about the larger population from which the sample was taken

strength

of a relationship between two quantitative variables: how much the value of one variable tells us about the value of the other

symmetric

A symmetric distribution has a balanced shape, showing that it’s just as likely for the variable to take lower values as higher values.

syntax error

errors where the computer cannot make sense of the code (e.g. - missing commas, missing parentheses, unclosed strings)

threats to validity

factors that can undermine the conclusion of a study

value

a specific piece of data, like 5 or "hello"

variable

a name or symbol that stands for some value or expression, often a value or expression that changes

y-intercept

the point where a line or curve crosses the y-axis of a graph