Chapter 14 Graphical Representation of Data Flashcards
Bar Chart
Chart in which (usually) the X-Axis represents a categorial variable and the Y-Axis can represent frequency, average, percentage etc.
Error Bar
On a bar chart, the vertical line at the top of each bar showing the possible range of error in measurements. The range represented can be +/- one standard deviation, +/- one standard error or a confidence interval for the mean
Line Chart
Chart joining continuous data points in a single line
Time Series
Line chart showing measures of a variable at progressive time intervals
Histogram
Chart containing whole of continuous data set divided into class intervals with each interval represented by a column proportional to a frequency in the interval
Frequency Polygon
Histogram showing only the peaks of class intervals
Exploratory Data Analysis
Close examination of data by a variety of means, including visual display, before submitting them to significance testing; recommended by Tukey
Stem and Leaf Chart
Exploratory data analysis tool showing every value in a data set but organised into class intervals to give a sideways histogram shape
Cumulative Frequency
Distribution (table or chart) that shows the number of cases that have occurred up to and including the current category
Box-Plot
Exploratory data chart showing median, central spread of data and position of relative extremes
Hinge Position
On a box-plot, the lower edge of the box where the first quartile falls and the upper edge where the third quartile falls
Lower Hinge
On a box-plot, the first quartile
Upper Hinge
On a box-plot, the third quartile
Hinge Spread
On a box-plot, the distance between the lower and upper hinges, i.e. the interquartile range (IQR)
Outer Fence
Extreme ‘whisker’ position on a box-plot being, for the lower fence, lower hinge - 1.5 X IQR, and for the upper fence, upper hinge + 1.5 X IQR. If there are no outliers then the fences are the maximum and minimum values.
