MIS Exam 2 - Chapter 2: Descriptive Statistics: Tabular and Graphical Displays

bar chart

Data graphed as a series of bars.

categorical data

use labels or names to identify categories of like items

class midpoint

halfway between the lower and upper limit

crosstabulation

can be used with categorical or quantitative variables

crosstab.: row or column percentages

can provide additional insight about the relationship between the two variables

simpson's paradox

the reversal of conclusions based on aggregate and unaggregated data

data dashboard

-widely used data visualization tool that provides timly, summary info in an easy to read and interpret format.

-organizes and presents KPIs used to monitor an organization or process

data visualization

-describes the use of graphical displays to summarize & present info about a data set.

-the goal is to communicate as effectively and clearly as possible the key info about the data

dot plot

simplest graph, horizontal axis shows range of values

frequency distribution calculations

relative frequency: frequency/n

percent frequency: frequency/n*100

histogram

a bar graph depicting a frequency distribution

symmetric skewness

Left tail is the mirror image of the right tail

moderately skewed

longer tail to the left

highly skewed right

longer tail to the right

pie chart

categorical data, presents relative frequency & percent frequency

quantitative data

numerical values that indicate how much or how many

distribution steps of quanti. data freq.

1. number of classes

2. width of the classes

3. class limits

relative frequency formula (quantitative variable)

frequency divided by total # of observations

scatter diagram

useful in exploring the relationship between two variables

positive relationship (scatter diagram)

as one increases, the other increases

no relationship (scatter diagram)

line appears flat

negative relationship (scatter diagram)

as one increases, the other decreases

side-by-side bar chart

-compare two variables

-each cluster of bars reps. one value of first variable.

-each bar within cluster reps. one value of second variable

stacked bar chart

each bar broken into rectangular segments of different colors

stem-and-leaf display

-shows both rank, order, & shape of distribution of data

-shows actual data values & easier to construct by hand

percent frequency distribution

frequency/n*100

relative frequency distribution

frequency/n

trendline

provides an approx. of the relationship