SPSS Basics for Institutional Researchers

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SPSS Basics for Institutional Researchers

• Gayle Fink
• Director of Institutional Research
• University System of Maryland
• gfink_at_usmd.edu

November 30, 2007
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Commonly Asked Questions

• 1. Will I be able to get copies of the slides
  after the event?
• 2. Is this web seminar being taped so I or others
  can view it after the fact?

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Commonly Asked Questions

• 1. Will I be able to get copies of the slides
  after the event?
• 2. Is this web seminar being taped so I or others
  can view it after the fact?

Yes
Yes
www.spss.com/airseries
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Welcome Agenda

• Explore a number of SPSS basic features that make
  data analysis easier
• Aggregate
• Date/Time Wizard
• Custom Tables
• Each feature will be demonstrated using census
  data
• Student registration activity file matched with
  course characteristics, or
• Student demographic file
• Answer typical IR questions with these features

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Demonstration

• If you are not automatically taken to the "Shared
  Application" screen during the demonstration,
  please click on the "Shared Application" button
  at the bottom of your screen.

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SPSS Version and Data File Detail

• SPSS 15.0
• Does not matter what version you are running
  features included!
• Registration Activity file (Community College)
• Student demographics
• Course information
• Time/Date/Type of Registration
• Instructional delivery/course type
• Student Demographic file (4-Year Institutions)
• Student Demographics
• Major
• Tuition Status
• Multiple Institutions and Multiple Years

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Aggregate Command

• AGGREGATE combines groups of cases in the active
  dataset into single cases and creates a new file
  or creates new variables in the active dataset
  that contain aggregated data.
• The values of one or more variables in the active
  dataset define the case groups. These variables
  are called break variables.
• A set of cases with identical values for each
  break variable is called a break group.
• Aggregate functions (mean, median, sum, etc.) are
  applied to source variables in the active dataset
  to create new aggregated variables that have one
  value for each break group.

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Aggregate Command Syntax Example

• AGGREGATE
• /OUTFILE'c\temp\temp.sav
• /BREAKgender marital
• /age_meanMEAN(age)
• /age_medianMEDIAN(age)
• /income_medianMEDIAN(income).
• AGGREGATE creates a new SPSS-format data file,
  temp.sav, that contains two break variables
  (gender and marital) and all of the new aggregate
  variables.
• BREAK specifies gender and marital as the break
  variables. In the aggregated file, cases are
  sorted in ascending order of gender and in
  ascending order of marital within gender. The
  active dataset remains unsorted.
• Three aggregated variables are created age_mean
  contains the mean age for each group defined by
  the two break variables age_median contains the
  median age and income_median contains the median
  income.

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Using Aggregate to Create a Student Demographic
File from a Registration Activity File
Student Demographic File
Registration File By student and course
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Lets Aggregate!

• To Aggregate a Data File
•  From the menus choose
•   Data   Aggregate...

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Lets Aggregate!

• Select one or more break variables that define
  how cases are grouped to create aggregated data.
• Select one or more aggregate variables.
• Select an aggregate function for each aggregate
  variable.
• Optionally, you can override the default
  aggregate variable names with new variable names,
  provide descriptive variable labels, and create a
  variable that contains the number of cases in
  each break group.

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Lets Aggregate!
Aggregate Functions
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Lets Aggregate!

• Saving Aggregated Results
• Add aggregate variables to the active dataset or
  create a new, aggregated data file.
• Add aggregated variables to active dataset. New
  variables based on aggregate functions are added
  to the active dataset. The data file itself is
  not aggregated. Each case with the same value(s)
  of the break variable(s) receives the same values
  for the new aggregate variables.
• Create a new dataset containing only the
  aggregated variables. The active dataset is
  unaffected.
• Write a new data file containing only the
  aggregated variables. Saves aggregated data to an
  external data file. The active dataset is
  unaffected.

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Aggregate Example
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Date and Time Wizard

• Why use this?
• Most dates/time in census files are text
• no functionality
• Common dates/time
• Birth date
• Registration date
• Course/Section start and end dates
• Course start/end times
• Suggestion about time
• Military time is easier to manipulate across
  applications
• Examples
• Checking age calculation
• Establishing N of weeks before day 1 of class a
  student registered for a course

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Using the Date and Time Wizard!

• To use the Date/Time Wizard on a Variable
•  From the menus choose
•   Transform   Date/Time Wizard...

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Using the Date and Time Wizard!

• Need to confirm that the Age calculation from the
  census extract is calculating age correctly
• How to calculate Age?
• Examples
• Current year minus birth year
• Day 1 date minus birth date
• Freeze date minus birth date
• Create a date/time variable from a string
  containing a date or time.
• Extract a part of a date or time variable.

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Using the Date and Time Wizard!

• Student demographic file we just built with only
  the birth date and age.
• Convert BIRTH_DATE to a date variable
• Extract BIRTH_YEAR from the new DOB variable
• Calculate different dates and compare to system
  calculation!

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Resulting Data file!
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Date and Time Wizard Example
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Custom Tables

• To Build a Table
•  Analyze   Tables    Custom Tables...
• Drag and drop one or more variables to the row
  and/or column areas of the canvas pane.
• Click OK to create the table.
• To delete a variable from the canvas pane in the
  table builder
• Select (click) the variable on the canvas pane.
• Drag the variable anywhere outside the canvas
  pane, or press the Delete key.
• To change the measurement level of a variable
• Right-click the variable in the variable list
  (you can do this only in the variable list, not
  on the canvas).
• Select Categorical or Scale from the pop-up
  context menu.

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Custom Tables
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Custom Tables

• What types of variables do you have?
• Categorical. Data with a limited number of
  distinct values or categories
• Nominal. A variable can be treated as nominal
  when its values represent categories with no
  intrinsic ranking (for example, the department of
  the company in which an employee works). Examples
  of nominal variables include region, zip code,
  and religious affiliation.
• Ordinal. A variable can be treated as ordinal
  when its values represent categories with some
  intrinsic ranking (for example, levels of service
  satisfaction from highly dissatisfied to highly
  satisfied). Examples of ordinal variables include
  attitude scores representing degree of
  satisfaction or confidence and preference rating
  scores.
• Scale. Data measured on an interval or ratio
  scale, where the data values indicate both the
  order of values and the distance between values.

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Custom Tables
Which variable is a scale variable? All the rest
are.?
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Custom Tables Example

• Build a multi-year/multi-institution student
  demographic profile
• For you think about using different
  divisions/locations/colleges instead of
  institutions
• Using a flat file that is sent to State
  coordinating board with data from 3 USM
  institutions
• Demographics/Residency
• Program/Level
• First-time flag
• Attendance Pattern/Credit hours
• Build a fact book trend table with gender,
  ethnicity, residency with totals

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Custom Tables
Column Variable Year
Where do you put Institution?
Change Variable Type
Row Variables Gender Ethnicity Residency
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Custom Tables Example
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Quick recap

• Learned how to
• Aggregate
• Use the Date/Time Wizard
• Build a custom table
• Need to take time to play with these features
  to become proficient
• VERY helpful for turning things around quickly

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Question Answer

• To ask a question over telephone, press 1
• Text questions by using QA tab in lower right

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For More Information

• In case you missed it recorded version and
  slides available at www.spss.com/airseries
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