Describing Data Visually (ch 3)

Trend Line

descriptive tool that may help you find patterns in (X, Y) data

Pareto Chart

displays categorical data, with categories displayed in descending order of frequency, so that the most common categories appear first

Arithmetic Scale

distances on the Y-axis are proportional to the magnitude of the variable being displayed

Logarithmic Scale

equal distances represent equal ratios

Left-Skewed

histogram has a longer left tail, with most data values clustered on the right side

Right-Skewed

histogram has a longer right tail, with most data values clustered on the left side

Symmetric

neither tail is longer on a histogram

Pie Chart

only convey a general idea of the data

Pivot Table

provides interactive analysis of a data matrix

Line Chart

sed to display a time series, to spot trends, or to compare time periods

Scatter Plot

shows n pairs of observations as dots on an X-Y graph

Dot Plot

simple graphical display of n individual values of numerical data

Stacked Column Chart

the bar height is the sum of several subtotals

Stacked Dot Plot

used to compare two or more groups

Shape

Are the data values distributed symmetrically? Skewed? Sharply peaked? Flat? Bimodal?

Center

What are the units of measurement? Are the data integer or continuous? Any missing observations? Any concerns with accuracy or sampling methods?

Measurement

What are the units of measurement? Are the data integer or continuous? Any missing observations? Any concerns with accuracy or sampling methods?

Variability

What are the units of measurement? Are the data integer or continuous? Any missing observations? Any concerns with accuracy or sampling methods?

Histogram

a graphical representation of a frequency distribution

Sturges' Rule

a guideline proposed by statistician Herbert Sturges, every time we double the sample size, we should add one bin

Bar Chart

a horizontal display of data

Ogive

a line graph of the cumulative frequencies

Frequency Polygon

a line graph that connects the midpoints of the histogram intervals, plus extra intervals at the beginning and end so that the line will touch the X-axis

Frequency Distribution

a table formed by classifying n data values into k classes called bins

Stem-and-Leaf Plot

a tool of exploratory data analysis (EDA) that seeks to reveal essential data features in an intuitive way

Column Chart

a vertical display of data

Outlier

an extreme value that is far enough from the majority of the data that it probably arose from a different cause or is due to measurement error