Time-Series
vs.
Cross Sectional
(MOVIE)
(SNAPSHOT)
Same population/sample
measured
Different populations/samples
at different times.
measured at the
same time
.

OIS 2340
–
Business Statistics
Chapters 1 & 2
3
Rankings and
Ordered
Categories
Categorical Codes
ID Numbers
Category Names
Interval/Ratio Data
Highest Level Data
Allows Complete Analysis
Ordinal Data
Higher Level Data
Allows Mid-Level Analysis
Nominal Data
Lowest Level Data
Allows Only Basic Analysis
*Data Measurement Levels
Nominal Data
Ordinal Data
Categorical (Qualitative) Data
Categorical (Qualitative) Data WITH
“Names”
ORDER OR RANK
“my favorite color”
“class rank”
“favorite sport”
“Level of education”
“gender”
Interval Data
Ratio Data
Numerical (Quantitative)
Numerical (Quantitative)
with a true 0
(Does 0 mean “none”?)
“temperature”
“age”
“income”
Measurements

OIS 2340
–
Business Statistics
Chapters 1 & 2
4
Summarizing QUALITATIVE Data
Tabular Summaries
1.
Frequency Distribution
Displays the
number
of observations in each of several categories or classes.
Can be generated with Excel’s COUNTIF function.
]
SOFT DRINK EXAMPLE
2.
Relative Frequency and Percent Frequency Distributions
Shows the
proportion
or
percentage
of items in each of several categories or
classes.
Relative Frequency
= Frequency of a Class ÷
n
, where
n
is the number of
observations.
Percent Frequency
= Relative Frequency x 100.
Useful for comparing similar sets of data with different sample sizes.
SOFT DRINK EXAMPLE FOLLOW UP
Graphical Summaries
1.
Bar Charts
May be used to show frequency, relative frequency, or percent frequency.
Provide a quick visual of what a frequency distribution shows in tabular form.
Bars should be separate to reinforce the distinctness of categories.
Bars are often colored (but don’t have to be).
Bars may run vertically (more common) or horizontally.