Introduction to SPSS Descriptive Statistics

Introduction to SPSS Statistics Program for the Social Sciences (SPSS) Commonly used statistical software package Very user-friendly How you will be doing statistics in graduate school

Introduction to SPSS Divided into “data view” & “variable view” Default is data view Data view – shows the data Variable view – summary of variables, options related to them Switch between them by: 1. clicking on tabs located on bottom left of screen 2. clicking on “View”  “Data/Variables” in top menu 3. pressing CTRL+T

Entering Data Can either enter data by hand or import from other programs (i.e. Excel) Hand entering Insert a variable by: 1.Right clicking one of the rows in variable view and selecting “Insert Variable” 2.Entering a “Name” in variable view and pressing “Enter” or “Tab” 3.Right clicking on a column in the data view and selecting “Insert Variable” 4.Clicking on the “Insert Variable” icon in the Toolbar 5.Clicking on “Data”  “Insert Variable”

Entering Data Define variables in variable view  Name = Name of variable displayed in data view  Type = Numeric, Comma, Dot, Scientific notation, Date, Dollar, Custom currency, & String  Width = # of digits displayed in data view  Decimals = # of decimal places displayed in data view  Label = Name of variable displayed when running analyses  Values = Value Labels – i.e. 1 = Male, 0 = Female  Missing = Values that the system will recognize as missing  Columns = # of columns used to display variable in data view  Align = variable left, right, or center aligned  Measure = scale on which variable is measured – Nominal, Ordinal, or Scale (Interval or Ratio)

Entering Data Importing Data Click “File”  “Open”  “Data” Select the file type in question If Excel: 1.Make sure top row of excel file lists variable names & the variables all have different names 2.After selecting the file, click Enter – make sure the box “Read variable names from the first row of data” is clicked 3.Make sure you variable are defined properly in the variable view

Menus File & Edit Menus Exactly the same as all Windows programs View Menu Allows you to customize the SPSS desktop Status Bar – “Processor Area” at the very bottom of the screen Toolbars Fonts Grid Lines Value Labels – Make sure this is selected if you want to use them Variables/Data view

Menus Data Menu Define Dates… = Inserts a Date variable Insert Variable Insert Case Go to Case… Sort Cases… = Ascending or descending order Transpose… = Switches cases and variables (former in columns and latter in rows) Merge Files – More on this later Split Files – More on this later Select Cases = If condition is satisfied, Random sample of cases, Based on time or case range, Use filter variable

Splitting and Merging Files Splitting 1. Click on “Organize output by groups” – grouping variable should be discrete (i.e. gender, hair color, etc.) 2. Click on grouping variable and move to “Groups Based on” box 3. Click “OK” Merging You can add either variables or cases If adding variables: 1.Make sure both files share at least one variable that is identical, the key variable (i.e. SubID) 2.Make sure both files are sorted by this variable 3.Make sure, in both files, all cases have data for this variable and there are no duplicate cases 4.Click on “Merge Files”  “Add Variables” 5.Find the file you wish to merge with the one you have open 6.The variable in the “Excluded Variables” box should be the key variable, denoted by a (+) indicating its presence in both files 7.Click on “Match cases on key variables in sorted files” 8.Move the key variable to the “Key Variables” box 9.Click “OK”

Menus Transform Menu Compute Name new variable in “Target Variable” box 2. Type equation in “Numeric Expression” box Recode – Into Same/Different Variable 1. Select variable(s) to recode and move to the “Variables” box 2. Click “Old and New Values” 3. Click “OK” Count… 1. Name new variable in “Target Variable” box 2. Select variable(s) with values to be counted & move to the “Numeric Variables” box 3. Click “Define Values…” 4. Click “OK” Rank Cases… 1. Select variable(s) to rank and move to the “Variable(s)” box 2. Click “Assign Rank 1 to” either “Smallest value” or “Largest value” 3. Click “OK”

Obtaining Descriptive Statistics Click on “Analyze”  “Descriptive Statistics”  Frequencies Use to determine counts on values of variables Cut scores and %iles

Frequencies

Descriptives Click on “Analyze”  “Descriptive Statistics”  Descriptives Use to get descriptive statistics (central tendency, variability, etc.) Use to convert variables to z-scores

Explore Click on “Analyze”  “Descriptive Statistics”  Explore Use to examine descriptive statistics by grouping variable

Explore