Positive and negative use of graphs
accuratly & succintly present information
reveal/conceal complicated data
Critical Skill
graphing in thr "information age
Technique for misleading
1. The False face validity Lie
Method seems to represent what it says, but does not actually
Ex - underlying as a measure of aggresion but really only yelling.
Ex - hours of sleep as a measure of depression and not condidering other variables
Techniques for misleading
2. Biased Scale Lie
Scaling to skew the results - slants info in a particular way - scae is puliing for a certian response.
Ex - 5- point Likert scale ranging from 1 (good) to 5 (perfect)
Techniques for misleading
3. The Sneaky Sample Lie
When participants are preselected or self-selected to provide data in such a ay that the data turn out in a particular way.
Ex - people are more likely to leave comment cards if they are very displeased or very satisfied at a restaurant.
Ex - Asking vegit
Techniques for misleading 4. 4. Interpolation Lie
Assumes that a value between 2 data points follow the same pttern - you should check to see that a reasonable number of in-between points has been reported.
Techniques for misleading
5. Extrapolation Lie
Assumes that a pattern will continue indefinintely - to avoid this, don't assume the pattern will continue
Ex - Popularity of CB radio was assumed to continue indefinitely
Ex - Ebook usage among students...
Techniques for misleading
6. The Inaccurate Values Lie
Using scale to distort data - telling the truth in one part of the data, but visually distorting it in another place.
Techniques for misleading
7. The Outright Lie
Making up data - people tend to make up data to lend an air of legitamacy to an otherwise weak argument.
Scatterplots and line graphs
are used to are used to depice relations between two scale variables.
Scatterplot
is a graph that depicts the relation between two scae variables. The values of each variable are marked along the 2 axis, and a mark is made to indicate the intersection of the 2 scores - the mark above the score on the x-axis and across from the score on
A range-frame
is a scatterplot or related graph thta indicates the range of the data on each axis; the lines extend only from the minimum to the maxium scores
A linear relation
between variables means that the relation between variables is best described by a straight line
A nonlinear relation
between variables means that the relation between variables is best described by a line that breaks or curves in some way
A line graph
is used to illustrate the relation between 2 scale variables; sometimes the line rpresents the predicted y scores for each x value, and sometimes the line represent change in a varible over time
A time plot or time series plot
is a graph that plots a scale variable on the y axis as it changes over an increment of time (e.g., second, day, century) labeled on the x-axis
A bar graph
is a visualdipiction of data when the independent variable is nominal or ordinal and the dependent varible is scale. Each bar typically represents the average value of the dependent variable for each category
A Pareto chart
is a type of bar graph in which the categories along the x-axis are orederd from highest bar on the left to the lowest on the right.
A pictorial graph
is a visual depiction of data typically used for an independent variable with few levels(categories) and a scale dependent variable. Each level uses a picture or symbol to represent its value on the scale dependent variable
A pie chart
is a graph in the shape of a circle with a slice for every level (category) of the independent variable. The size of each slice represents the porportion (or percentage) of each level.
Chartjunk
is any unnecessary information or feature in a graph that detracts from a viewer's ability to understand the data.