Transcript Mod 2 - Quantitative Data - WikiTutor

Quantitative Data
Workshop on
Assessment of Academic
Support Programs
Agenda
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What to assess
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Collecting the Data
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Survey, questionnaire etc.
Methods
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The research question
Accuracy of data
Assessing the Data
Presenting the Data
Statistics
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Statistics are
derived from the
data
Statistics are
descriptions of data
Statistics are meant
to simplify the data
Numbers are your friend
© 1984-1994 T/Maker Co.
What to assess
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Research Questions
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Experimental – requires a treatment
or intervention and participants that
are randomly assigned
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Descriptive – requires participants
and data. There is no treatment
effect.
What to assess - Experimental
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First things first!
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Experimental – requires a treatment or intervention.
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Variables
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Independent
Dependent
What to assess - Experimental
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First things first!
 Research Design
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True Experimental
Quasi-Experimental
What to assess - Descriptive
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Research Questions
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Descriptive – requires participants
and data. There is no treatment
effect.
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Descriptive research is used to describe.
How to collect the data
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Survey
Questionnaire
Interview
Ex Post Facto
Observation
How to collect the data
We will focus on the following:
 Survey
 Questionnaire
 Ex Post Facto
Methods
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Accurate record keeping
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Junk in - Junk Out!
Database management
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Can be Access, Excel or
other comprehensive
system.
How to assess the data
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When collecting data, we should look at the end product. What
do we want to find out? The next question will be, WHAT
ARE THE DATA???
When we are discussing data we should know a few terms:
 Nominal data
 Ordinal Data
 Interval Data
 Ratio Data
“Nominal and ordinal data are usually referred to as qualitative
data, and interval and ratio data are referred to an quantitative
data.”
Further Clarification
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Nominal Data
Ordinal Data
Interval Data
Ratio Data
Terms are Dull, but
Important
How to assess the data
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What are the Data
Statistics
Measures of central tendency
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Mean
Median
Mode
Measures of variability
How to assess the data
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MORE ON Measures of
central tendency
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Mean
Median
Mode
Analyze these data...
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Mean, median, mode
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4
5
5
8
6
6
7
10
9
4
3
8
10
3
11
7
4
6
5
6
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sample size (n)
Sum S
mean=average=S/n
median = halfway
mode = most
common
How to assess the data
Quartile and Standard Deviation
How to assess the data
Percentile (not percentage)
For Example
How to assess the data
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The use of SPSS
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If you wish to do the statistical analysis easier, I
would recommend SPSS or similar software.
Descriptive statistics include: mean, median,
mode, sum, percentiles, quartiles and standard
deviation are all calculated by the push of a few
buttons.
How to present the data
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First, who is the audience?
Keep it simpler and direct
with backup statistics to be
presented if necessary.
The use of tables, bar charts,
scatter diagrams, line
graphs, and so on is
preferred to long paragraphs.
How to present the data
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Tables should always have:
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Numerical data in the table should be written to the
proper number of significant digits.
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Title
Column headings with brief descriptive name, symbol and
appropriate units.
The decimal points in a column should be aligned.
Tables should always be referenced and discussed (at
least briefly) in the body of the text of the document
containing the table.
Table Example
Age and Gender of Student’s
Receiving Tutoring Services
Mean
Age
Gender
21.4
22.6
Males
Females
Receiving Tutoring Population vs.
General Population by Hours Worked
Hours Worked
1-5
6-10
11-15
16-20
21-25
>26
Total
Tutored
Student
22
12
7
15
21
23
100
General
Population
26
23
11
17
8
15
100
Graphs
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Proper graphing of data involves several
steps:
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Select appropriate graph type
Select scale and gradation of axes, and
completely label axes
Plot data points, then plot or fit curves
Add titles, notes, and or legend
Graphs
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Each graph must include:
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A descriptive title which provides a clear and concise
statement of the information being presented
A legend defining point symbols or line types used for
curves needs to be included
Labeled axes
Graphs should always be referenced/discussed in the
body of the text of the document containing the table.
Titles and Legends
Each graph must be identified with a
descriptive title
 The title should include clear and concise
statement of the information being presented
 A legend defining point symbols or line types
used for curves needs to be included
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Axis Labels
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Each axis must be labeled
The axis label should contain the name of the
variable and its units.
The units can be enclosed in parentheses, or
separated from the label by a comma.
Length (km)
Receiving Tutoring Population vs.
General Population by Hours Worked
30
25
23
22
15
15
12
10
23
21
20
17
15
Tutor
11
8
7
General
5
Hours Worked
>2
6
21
-2
5
16
-2
0
11
-1
5
610
0
15
Number of
Participants
26
Receiving Tutoring Population vs.
General Population by External Locus of
Control
25
20
17.19
15
13.61
10
Receiving
Tutoring
General
Population
5
Mean Score for External Locus of Control
Receiving Tutoring Population vs. General
Population by External Locus of Control
25
20
20.63
20.05
18.57
16.16
15
19.84
18.57
16.07
13.36
10
Tutoring
Population
5
Anxiety
Efficacy
Mean Score
for Motivation
to Avoid
Failure
Motivation
For Success
General
Population
Pie Chart and Bar Graph with
the same data
2. Bar Graph
1. Pie Chart
Travel Expenses
Travel Expenses
Motel
Gas
18
16
14
12
10
8
6
4
2
0
Food
Gas
44%
Food
31%
Expenses ($)
Motel
26%
Data Points and Curves
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Data Points are plotted using symbols
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The symbol size must be large enough to easily
distinguish them
A different symbol is used for each data set
Data Points are often connected with lines
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A different line style is often used for each data
set
Building a Graph In Excel
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Select the data that you want to include in the chart by
dragging through it with the mouse.
Then click the Chart Wizard
Building the Graph
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Choose XY
(Scatter), with
data connected
by lines if
desired.
Click “Next”
Building the Graph
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Make sure that the
series is listed in
columns, since your
data is presented in
columns.
Click the Series tab to
enter a name for the
data set, if desired.
Choose “Next”
Building the Graph
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Fill in Title and Axis information
“Next”
Building a Chart
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Select “As new sheet” to create the chart on it’s own sheet
in your Excel file, or “As object in” to create the chart on
an existing sheet
“Finish”
Creating a Secondary Axis
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This is useful when the data sets cover very different
ranges.
Right click on the line (data
series) on the chart that you
want to associate with a
secondary axis.
Select “format data series”
Select the Axis tab, then
“Plot series on secondary
axis” as shown.
“OK”
Editing/Adding Labels
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Now you can go back to the “chart options” to add labels
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Click the chart in a blank area, then either right click and select chart
options or choose chart options from the “Chart” menu
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Fill in or edit the
axes labels, title,
etc.
Click “OK”
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Result
Use of the Data
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Assessment / evaluation studies
Program changes / upgrades
Procuring new equipment
Adding Personnel
Etc.
Discussion Board
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Please go to the Discussion board and respond
to the prompt you will find for this module.
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Thank you.