Software for data management: The contribution of Stata

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Software for data management The contribution of
Stata

• Dr Karen Robson, Senior Research Fellow, The
  Geary Institute, University College Dublin,
  Ireland

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Getting acquainted with Stata

• StataCorp develops and distributes Stata,
  software for statistical analysis.
• Stata is available for Windows, Macintosh, and
  Unix computers.
• Stata is used by medical researchers,
  biostatisticians, epidemiologists, economists,
  sociologists, political scientists, geographers,
  psychologists, social scientists, and other
  research professionals needing to analyze data.
  Gaining popularity in the social and medical
  sciences
• Particularly useful for handling large-scale
  longitudinal data

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Stata SE (for large data sets)

• can analyze datasets with as many as 32,766
  variables, and the only limit on observations is
  the amount of RAM on your computer
• can handle string variables with a maximum length
  of 244 characters
• can handle matrices up to 11,000 x 11,000.
• requires at least 512 megabytes of RAM and 80
  megabytes of disk space

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Stata/Intercooled (the standard one)

• can analyze datasets with as many as 2,047
  variables, and the only limit on observations is
  the amount of RAM on your computer
• can handle string variables with a maximum length
  of 244 characters
• can handle matrices up to 800 x 800.

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Small Stata

• A smaller, student version of Stata (for
  educational purchases only)

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Stata MP

• The fastest version of Stata (for dual-core and
  multicore/multiprocessor computers)
• Stata/MP is the fastest and largest version of
  Stata.

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Resources

• StataCorp website (www.stata.com)

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Resources

• StataCorp website (www.stata.com)
• Timberlake website (www.timberlake.co.uk)

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Resources

• StataCorp website (www.stata.com)
• Timberlake website (www.timberlake.co.uk)
• UCLA Stata portal (http//www.ats.ucla.edu/stat/
  )

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Resources

• StataCorp website (www.stata.com)
• Timberlake website (www.timberlake.co.uk)
• UCLA Stata portal (statcomp.ats.ucla.edu/stata)
• Statalist (www.hsph.harvard.edu/statalist)

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Resources

• StataCorp website (www.stata.com)
• Timberlake website (www.timberlake.co.uk)
• UCLA Stata portal (statcomp.ats.ucla.edu/stata)
• Statalist (www.hsph.harvard.edu/statalist)
• Stata Journal (www.stata-journal.com)

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As well, available Dec 2008
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Launching Stata

• OS contingent
• Default window preferences
• Window preferences fully adjustable
• Auto memory set

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Comparing with SPSS

• Start up differences

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Comparing with SPSS

• Start up differences
• With data file open

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Comparing with SPSS

• Start up differences
• With data file open
• Viewing data
• data viewer, data editor

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Comparing with SPSS

• Start up differences
• With data file open
• Viewing data
• data viewer, data editor
• Viewing variables

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Comparing with SPSS

• Start up differences
• With data file open
• Viewing data
• data viewer, data editor
• Viewing variables
• Viewing output/commands
• output window buffer, log files

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Comparing with SPSS

• Start up differences
• With data file open
• Viewing data
• data viewer, data editor
• Viewing variables
• Viewing output/commands
• output window buffer, log files
• Syntax and do files

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Variable window
INPUT Stata command window Do file Pull-down menu
Review window
Computation
RESULTS Output window Log file
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Advantages and disadvantages of Stata

• User driven
• Free STBs
• Dedicated journal
• Web active
• Memory requirements
• Backward compatible

• Change!
• SPSS dominance
• Orientated to writing syntax/code
• Pull-down windows debate! Now in version 8 forward

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Advantages and disadvantages of Stata

• Easier code
• Easier data handling
• Clarity of operations/ feedback
• Results table function

• Before version 8, limited graphics
• Now, complex graphics
• Variable labelling
• Editing of output

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Advantages and disadvantages of Stata

• Copy and paste

• Nested/master do files
• Flexible terminology
• Setting types of data
• Interactive help
• Switch output (log file) on/off

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Overview of analytic techniques

• Too numerous to mention!
• Comprehensive manuals
• A selection
• All types of regression
• Survey package
• Epidemiological package
• Multilevel modelling
• Time series functions
• Cluster analysis

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Data

• Data files .dta
• Stat/Transfer software

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Stata using wide and long file formats

• Wide file formats (everything you add goes to the
  right of the existing data)
• Long file formats (everything you add goes
  underneath the existing data)

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