Data Visualization

spaghetti chart

a chart depicting possible flows through a system using a line for each possible path

shot chart

a chart that displays the location of shot attempts by a basketball player during a basketball game with different symbols or colors indicating successful and unsuccessful shots

bar chart

a chart that shows a summary of categorical data using the length of horizontal bars to display the magnitude of a quantitative variable

column chart

a chart that shows numerical data by the height of a column for a variety of categories or time periods

high-low-close stock chart

a chart that shows the high value, low value, and closing value of the price of a share of stock over time

funnel chart

a chart that shows the progression of a numerical variable to typically smaller values through a process, for example, the percentage of website visitors who ultimately result in a sale

treemap

a chart that uses the size, color, and arrangement of rectangles to display the magnitudes of a quantitative variable for different categories, each of which are further decomposed into subcategories

stacked column chart

a column chart that shows part-to-whole comparisons, either over time or across categories. different colors or shades of color are used to denote the different parts of the whole within a column

color wheel

a common chart used to show the relationships between primary secondary and tertiary hues for a primary color model

data dashboard

a data visualization tool that gives multiple outputs and may update in real time

proximity

a gestalt principle stating that people consider objects that are physically close to one another as belonging to a group

enclosure

a gestalt principle that states that objects that are physically enclosed together are seen as belonging to the same group

connection

a gestalt principle that states that people interpret objects that are connected in some way as belonging to the same group

control chart

a graphical display in which a variable of interest is plotted over time relative to lower and upper control limits

stock chart

a graphical display of stock prices over time (high-low-close is type of stock chart)

scatter chart

a graphical representation of the relationship between two quantitative variables. one variable is shown on the horizontal axis and the other is shown on the vertical axis

flicker

a movement type of pre-attentive attribute

motion

a movement type of pre-attentive attribute that involves directed movement and can be used to show changes within a visualization

random variable

a quantity whose values are not known with certainty

bubble chart

a scatter chart that displays a third quantitative variable using different sized dots, which we refer to as bubbles

diverging color scheme (diverging color palette)

a set of colors used in a chart or in a series of related charts to describe values of a quantitative variable for which there is meaningful reference value, such as a target value or the mean (heat map colors)

categorical color scheme (categorical color palette)

a set of colors used to describe a categorical variable when the categories have no inherent ascending or descending order

sequential color scheme (sequential color palette)

a set of colors used to describe the values of a quantitative variable or a categorical variable when the categories have an inherent ascending or descending order (map of america example, gradient coloring of same color)

frequency distribution

a summary of data that shows the number of (frequency) of observations in each of several nonoverlapping bins(classes)

orientation

attribute associated with form. it refers to the relative positioning of an object within a data visualization

form

attributes of orientation, size, shape, length, and width

geographical map

chart that shows characteristics and the arrangement of the geography of our physical reality

clustered column chart

chart that shows multiple variables of interest on the same chart, with the different variables usually denoted by different colors or shades of a color

sankey chart

chart that typically depicts the proportional flow of entities where the width of the line represents the relative flow rate compared to the widths of the other lines

cross-sectional data

collected from several entities at the same or approximately the same point in time

analogous colors

colors adjacent to each other on a color wheel

complementary colors

colors that are directly opposite each other on a color wheel

serif fonts

contain serifs - traditional text for print/paper viewing

categorical variable

data for which categories of like items are identified by labels or names. arithmetic operations cannot be performed on categorical variables

categorical data

data for which categories of like terms are identified by labels or names. arithmetic operations cannot be performed on categorical data

quantitative variable

data for which numerical values are used to indicate magnitude, such as how many or how much (can be counted up)

hierarchical data

data that can be represented with a tree-like structure where the branches of the tree lead to categories and subcategories

hue

defines the base of the color

variation

differences in values of a variable over observations

sans-serif fonts

do not contain "serifs" - cleaner text for screen viewing

warm hues feelings

energy passion and danger (yellow, orange, red)

preattentive attributes

features of a data visualization that can be processed by iconic memory. pre-attentive attributes related to visual perception are generally divided into four categories: color, form, spatial positioning, and movement

relative frequency

frequency measure in a distribution analysis that computes the fraction or proportion of observations in each of several nonoverlapping bins (classes)

choropleth map

geographic map that uses shades of a color, unique colors, or symbols to indicate quantitative or categorical variables by geographic region or area

length

horizontal vertical or diagonal distance of a line or bar/column

distribution

how items are dispersed

correlation/relationship

how two variables are related to one another

spatial positioning

location of an object within some defined space

prescriptive analytics

mathematical or logical models that suggest a decision or course of action (ie. mathematical optimization models, decision analysis, and heuristic or rule-based systems)

data-ink ratio

measures the proportion of "data-ink" to the total amount of ink used in a table or chart where data-ink is the ink used that is necessary to convey the meaning of the data to the audience

quantitative data

numerical values are used to indicate magnitude, such as how many or how much. Arithmetic operations such as addition subtraction multiplication and division can be performed on quantitative data

color

pre-attentive attribute for data visualization that includes the attributes of hue, saturation, and luminance

color

property of an object that results from the way the object reflects or emits light

colorblindness

reduced ability to accurately perceive some colors

gestalt principles

refer to the guiding principles of how people interpret and perceive what they see

size

refers to the relative amount of 2D space that an object occupies in a visualization

shape

refers to the type of object used in data visualization

ranking

relative order of items

saturation

represents the amount of gray in the color and determines the intensity or purity of the hue in the color

luminance

represents the relative degree of black or white in the color (dark to light)

population

set of all elements of interest in a particular study

color scheme

set of colors (hues, saturations, and luminances) that are to be used in a data visualization or a series of related data visualizations

funnel chart

shows progression of quantitative variable for various categories from larger to smaller values

line chart

similar to scatter charts in that each point represents a pair of quantitative variable values, but in a line chart, a line connects the points

serifs

small end-of-stroke features that are visual in fonts

cool hues feelings

soothing, calm, reassuring (purple, blue, green)

similarity

states that people consider objects with similar characteristics as belonging to the same group

sample

a subset of the population

primary hues

RED GREEN BLUE

When should tables be used instead of a chart?

- needs to refer to specific numerical values - needs to make precise comparisons between different values and not just relative comparisons - values being displayed have different units or very different magnitudes.

charts that show ranking

-bar -column

Charts that show composition

-bar -stacked bar -stacked column -treemap -waterfall -funnel

charts to avoid

-radar chart -pie chart -area chart -combo chart

Charts that show distribution

-scatter -bubble -column -bar -choropleth map

Charts that show a relationship

-scatter -bubble -line -stock -column -bar -heat map

big data

Any set of data that is too large or complex to be handled by standard data-processing techniques using a typical desktop computer. Big data includes text, audio, and video data.

time series data

Data collected over several points in time (minutes, hours, days, months, years, etc.)

Data Visualization

The graphical representation of data and information using displays such as charts, graphs, and maps

bins

The nonoverlapping groupings of data used to create a frequency distribution. Bins for categorical data are also known as classes

Analytics

The scientific process of transforming data into insights for making better decisions

predictive analytics

techniques that use mathematical models constructed from past data to predict future events or better understand the relationship between variables (ie. regression analysis, time series forcasting, computer simulation, and predictive data mining)

decluttering

the act of removing the non-data-ink in the visualization that does not help the audience interpret the chart or table

four v's - volume

the amount of data generated

cognitive load

the amount of effort necessary to accurately and efficiently process the information being communicated by a data visualization

color symbolism

the cultural meanings and significance associated with color

four v's - variety

the diversity in types and structures of data generated

white space

the portion of a data visualization that is devoid of markings

short-term memory

the portion of memory that holds information for about a minute. it utilizes chunking, or grouping things together to hold about four chunks of visual information at one time

iconic memory

the portion of memory that is processed fastest. it is process automatically and the information is held there for less than a second

long term memory

the portion of memory where information is stored for an extended amount of time. most long-term memories are formed through repetition and rehearsal but can also be formed through clever use of story telling

visual perception

the process through which our brains interpret the reflections of light that enter our eyes

four v's - veracity

the reliability of the data generated

descriptive analytics

the set of analytical tools that describe what has happened (ie. data queries, reports, descriptive summary or statistics, and data visualization)

four v's - velocity

the speed at which the data are generated

color psychology

the study of the innate relationships between color and human behavior

width

thickness of the line or bar/column

heat map

two dimensional graphical representation of data that uses different shades of color to indicate magnitude

waterfall chart

visual display that shows the cumulative effect of positive and negative changes on a variable of interest. the basis of the changes can be time or categories and changes are represented by the columns anchored at the previous time or categories cumulative level

4 V's

volume velocity variety veracity

composition

what makes up the whole of an entity under consideration