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SPSS

• Recently it has gone through a name change so your icon on your computer may be under a different name (i.e. PASW- Predictive Analytics SoftWare).

• IBM purchased the company and said they are going to change the name to IBM-SPSS or SPSS: An IBM Company

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What is SPSS?• Statistical software: • Statistical Package for the Social Sciences• There are lots of others

– SAS– STATA– R– SHAZAM– Specialized software

• HLM• LISREL• BUGS

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Why SPSS?

• Although SPSS is not the most powerful statistical software - It is the easiest to learn and use!!!!!!

• It is very flexible and can do most everything we need

• It can examine a large amount of data very quickly

• It is competitively priced

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Where to start?

• Get some data

• In practice you would develop a research question first, a theory, hypotheses, etc. before collecting and analyzing data

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Sources of data• ICPSR - http://www.icpsr.umich.edu/icpsrweb/ICPSR/

• Free for universities that subscribe (UNLV does)

• For now we have a dataset on our course website and WebCampus

• http://faculty.unlv.edu/kfernandez/methods1.htm

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General Social Survey

• NORC (National Opinion Research Center) located at the University of Chicago

• Telephone survey since 1972

• Free to anyone

• http://www.norc.org/GSS+Website/

• It is big so use the edited 2002 version located on our course website

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General Social Survey• The dataset is huge with hundreds of

survey items (variables). • The dataset we are using today has been

edited to include only 47 variables• This is also an older dataset (sometime

after 1996).• The NORC website has a free 2010 version

if you are interested.• This could be a dataset you use for your

research design assignment

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The Basics

• This is a one level, rectangular dataset

• What do the rows represent?

• What do the columns represent?

• This dataset could be connected to other datasets to create multiple-level datasets

• i.e. individual, state, country

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First things first

• Setting the options will make life easier– Go to the pull down menu “edit”– Select “Options”– Select the “General” tab at the top– Under “Variable List” click Display Names and

Alphabetical– Now select the “Output Labels” tab– Make sure they all say Names and Labels or

Values and Labels

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Lets get our feet wet

• Most tools will be under the “analyze” pull down menu

• Select “Descriptive Statistics” and then “Frequencies”

• Find the variable “Tvhours”. The list should be alphabetical now. Move it to the “Variables” box and click ok.

• What does this table mean?

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Missing Data and Outliers

• Is there anything strange in any of the responses?

• What about missing data?

• How many respondents didn’t answer the question?

• NAP = Not Appropriate; NA = Not Answered

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Recoding• Variables often need to be cleaned or

recoded so that they can be used in a statistical model

• For example find the variable “income”

• Run a frequency

• There is a value that if not changed will really mess up your analysis

• What is it and why is it a problem?

• What do we need to do?

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Recoding• Select the “Transform” pull down menu

• Click the recode into the same variable

• WARNING, WARNING

• Usually I choose the “recode into different variable” because if you make a mistake you will forever change that variable and won’t be able to go back. Always have a backup of your dataset that is untouched so you can start over if you need to.

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Recoding• Select “income”

• Click “Old and New Values”

• In the Old Value type “24”

• In the new value select “System-Missing”

• Click “Add”

• Click “Continue”

• Now Click OK

• Rerun the frequency for income

• Now 23 is the highest value, not “refused”

The End

• Hand in homework #2

• Remember homework #3 is due Feb. 16

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