Week 2 2 CategoricData

8/12/2019 Week 2 2 CategoricData

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STATISTICSWEEK 2-2

Prepared by Abdul Hakim, PhD

Organizing and Tabulating

Categorical Data

FE-UII


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The summary Table

A table that summarizes some characteristic of categorical

data.

e.g. Data 2: Classification of Colleges and Universities in

North Carolina


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The Bar Charts

These charts are useful to express the information provided in

the above table.

Some suggestions to construct a bar chart.

o The bar should be constructed horizontally.

o All bars should have the same width.

o Spaces between bars should range from one-half the width of

a bar to the width of a bar.

o Scales and guidlines are useful aids in reading a chart and

should be included. The zero point or origin should beindicated.

o The axes of the chart should be clearly labelled.

o Any keys to interpreting the chart may be indicated within the

body of the chart or below the body of the chart.

o Footnotes of source notes, when appropriate, are presented


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Pie Charts

When the appropriate

software is not

available, you will need

a compass. Since a full

circle has 360, you

should multiply the

percentage with 360 to

obtain the appropriate

degrees for each

category. For example,

NU is 8,9%, so theappropriate degrees is

8,9% * 360 = 32

Percentage pie chart depicting the institutional

classification of 45 colleges and universities inNorth Carolina


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The Dot Charts

In a dot chart, each category is depicted by a thin

dashed line tipped with a lrge dot, with the length of the

line representing the frequency or percentage of

observations falling into a category.

To construct a dot chart, the following suggestions are

made.

The thin dashed lines should be constructed

horizontally.

Spacing between the thin dashed lines should be equal.

A horizontal scale showing the percentage at the bottom

of the frame should be included.

Footnotes or source notes, as appropriate, appear afterthe title of the chart at the bottom edge of the charts


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The Dot Charts

Percentage dot chart depicting the institutional classification of45 colleges and universities in North Carolina


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Graphing Categorical Data:

The Pareto Diagram

The pareto diagram is a special type of vertical bar chart

in which the categorized responses are plotted in the

descending rank order of their frequencies and

combined with a cumulative polygon on the same scale.


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Tabularizing Categorical

Data: Contingency Tables

This graph is not completed, Try Excel 2003 Version.


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Tabularizing Categorical Data:

Contingency Tables and Supertable

In order to explore any possible pattern or relationship

between type of institution and the college counsel

institutional classification, it is useful first to convert

these results into percentage based on:

The overall total,

The row total,

The column total.


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Contingency Tables

Contingency tables displaying type of institution and institutional

classification for 45 coleges and universities in North Carolina

(percentage based on overall total)


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Contingency Tables



(percentage based on overall raw total)


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Contingency Tables



(percentage based on overall column total)


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Supertable

Supertable is a table that present data containing several

categorical variables. A supertable is essentially a collection of

contingency tables, each has the same column variable categories.

The data in each cell of the table are always given as a percentage

of its corresponding row total. This permits line-by-line comparison

for the categories within a particular row variable as well as for thecategories among the various row variables.


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Supertable

A supertable for some possible relationships between various

features and institutional classification at 45 colleges and

universities in North Carolina

Week 2 2 CategoricData

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