Chapter 3: Visual Displays of Data

Question 1

Techniques for Misleading with Graphs

Answer 1

False Face Validity Lie - Occurs when the method seems to represent what it says, but when we did a little deeper, it does not
Biased Scale Lie - Slants information in a particular way
The Sneaky Sample Lie - when people who participate in a study are preselected in such a way that the data turn out in a particular way
The Interpolation Lie - There is an unreasonable number of in-between data points being reported
The Extrapolation Lie - Assumes knowledge of information outside the study
The Inaccurate Values Lie - Sometimes involves telling the truth in one part of the data but visually distorting it in another place
The Outright Lie - Lying for the sake of producing a specific number

Question 2

Types of Graphs

Answer 2

Scatterplot, Line Graphs, and Bar Graphs

Question 3

Scatterplot

Answer 3

A graph that depicts the relation between two scale variables. The values of each variable are marked along the two axes. A mark is made to indicate the intersection of the two scores for each participant. The mark is above the participant’s score on the x-axis and across from the score of the y-axis.

Question 4

Similarity between scatter plots and line graphs

Answer 4

They are both used to depict relations between two scale variables

Question 5

Range Frame

Answer 5

A scatterplot or related graph that indicates the range of the data on each axis; the lines extend only from the minimum to the maximum scores

Question 6

How to create a scatterplot

Answer 6

1. Organize the data by participant; each participant will have two scores, one on each scale variable
2. Label the horizontal x-axis with the name of the independent variable and its possible values, starting with 0 if practical
3. Label the vertical y-axis with the name of the dependent variable and its possible values, starting with 0 if practical
4. Make a mark on the graph above each study participant’s score on the x-axis and next to his or her score on the y-axis
5. To convert to a range-frame, simply erase the axes below the minimum score and above the maximum score

Question 7

Linear Relation

Answer 7

The relation between variables is best described by a straight line

Question 8

Nonlinear Relation

Answer 8

Best described by a line that breaks or curves in some way

Question 9

Line Graph

Answer 9

Used to illustrate the relation between two scale variables; sometimes the line represents the predicted y scores for each x value, and sometimes the line represents change in a variable over time

Question 10

Line of best fit

Answer 10

Allows us to use the x value to predict the y value

Question 11

Time Plot or Time Series Plot

Answer 11

A graph that plots a scale variable on the y-axis as it changes over an increment of time (second, day, century) labeled on the x axis; possible to graph several scale variables at the same time so the viewer can compare the trends of two or more variables over time

Question 12

Steps to Create a Time Plot

Answer 12

1. Label the x-axis with the name of the independent variable and its possible values. The independent variable should be an increment of time
2. Label the y-axis with the name of the dependent variable and its possible values, starting with 0 if practical
3. Make a mark above each value on the x-axis at the value for that time on the y-axis
4. Connect the dots
5. To convert to a range-frame, erase the y-axis below the minimum y value and above the maximum y value

Question 13

Bar Graphs

Answer 13

Visual depictions of data when the independent variable is nominal or ordinal and the dependent value is a scale. Each bar typically represents the average value of the dependent variable for each category; highlight differences between averages and percentages

Question 14

Pareto Chart

Answer 14

Type of bar graph in which the categories along the x-axis are ordered from the highest bar on the left to the lowest bar on the right

Question 15

Pictorial Graph

Answer 15

Visual depiction of data typically used for an independent variable with very few levels and a scale dependent variable. Each level uses a picture or symbol to represent its value on the scale dependent variable

Question 16

Pie Chart

Answer 16

Graph in the shape of a circle with a slice for every level of the independent variable. The size of each slice represents the proportion (or percentage) of each category

Question 17

What graph to use if there is one scale variable (with frequencies)

Answer 17

Histogram or a frequency polygon

Question 18

What graph to use if there is one scale independent variable and one scale dependent variable

Answer 18

Scatterplot or a line graph

Question 19

What graph to use if there is one nominal or ordinal independent variable and one scale dependent variable

Answer 19

Bar graph or a pareto chart

Question 20

Chartjunk

Answer 20

any unnecessary information or feature in a graph that detracts from a viewer’s ability to understand the data

Question 21

Dependent Variable

Answer 21

Variable researchers are trying to predict

Question 22

Independent Variables

Answer 22

What variables did the researchers use to predict the dependent variables