Graphs show
a visual representation of data that has been collected. Samples
of the different kinds of graphs are listed below.
Line
Plot
A line plot indicates the location of data points along a segment
of the number line. The following line plot depicts the number
of hits made during a baseball game.
Pictograph
A pictograph uses a repeated picture of a symbol in a bar graph
form to represent data. The key tells the value of one symbol.
Bar
Graph
A bar graph uses parallel bars, either horizontal or vertical,
to represent counts for several categories. One bar is used
for each category and the length of the bar represents the count
for that category.
Stem
and Leaf Plot
A stem and leaf plot lists exact values in a meaningful array.
It is especially useful when the data set covers a range of
25 numbers or more. On a real-number line, the data might appear
crowded on a line plot, making it difficult to recover the exact
numerical values.
Data set
= grams of fat content in cereal:
55, 48, 31, 32, 33, 38, 20, 25, 28, 28, 10, 10, 13, 13, 14,
14, 14, 15, 19, 19, 3, 4, 5, 8, 9
Scatter Plot
A scatter plot shows the relationship between paired measurements
by plotting each ordered pair on a coordinate grid. The first
number of the pair is marked off along the horizontal axis (or
the x axis) and the second number is marked off along the vertical
axis (or the y axis).
These definitions
are from Bereska, C., Bolster, L., & Bolster, C. et.al.
(1998). Exploring Statistics in the Elementary Grades, Book
1. White Plains, NY: Dale Seymour Publications.
