SPSS The Basics. Jennifer Thach RHS Assessment Office March 3 rd, 2014

Transcription

1 SPSS The Basics Jennifer Thach RHS Assessment Office March 3 rd, 2014

2 Why use SPSS? - Used heavily in the Social Science & Business world - Ability to perform basic to high-level statistical analysis (i.e. modes, averages, means, percentages to regressions, t-test, ANOVA, Factor Analysis) - Capable of holding large amounts of data (thousands!) - Easy to clean, sort and move data around - Ability to track information/changes made using output - Ideal for high level confidential data (because you have the ability to password protect documents and not many have access to SPSS)

3 Accessing SPSS On all Academic Computers at Michigan State University SPSS is installed and available to MSU users to utilize. In order to get to SPSS 1) 2) All Programs 3) Math Apps 4) IBM SPSS Statistics

4 Getting Started Once you have saved SPSS documents on File. Open an existing data file saved Online IBM tutorial (Help) New Empty Dataset Syntax Open an existing Output file or Syntax saved Import Data from Excel or Access

5 How SPSS works. Output A record of all of your activity during a session working with data & where your analyzes will be displayed Data Editor Where all of your data is housed (2 components) Data View Where all of your participant data (numbers is housed) Variable View - Information about what each variable is (variable name, measure, coding information, etc)

6 The Variable View In order to keep track of the numbers and different variables in the Data View the Variable View helps you to stay organize as well as serve as a dictionary or a phone book of what the numbers mean. Name Variable name (no spaces) Type what kind of data do you have? (numeric, date, dollar amounts, string (word text) Width how much information you want to show in a column Decimals - # of values after a decimal is recorded Label Description of what the Variable is (spaces allowed here!) Values Dictionary reference for coded values and numbers what does each number mean? Measure Nominal, Ordinal, Scale Nominal labels or names with no numerical significance (i.e. gender, hair color, neighborhood) Ordinal - order of values is important, but the difference between values do not matter (i.e. Likert Scales very unsatisfied to very satisfied) Scale numeric values with an order of values and a difference between values (i.e. G.P.A. averages, temperature) Missing Values Do you have any missing values (usually 999) that you don t want included in analysis

7 Importing Excel Data into SPSS 2 ways to do this: Open up SPSS Statistics Start All Programs Math Apps SPSS Create new query using Database Wizard Ok Excel Files Browse Insert document In a current SPSS Statistics open window File Open Data Types of File (change this to Excel) Insert Excel Document Open

8 Imported Data View Information that was displayed in the Excel document is now displayed in the Data View Like in Excel, everything in row 17 is regarding one individual

9 Imported Variable View Information provided in the first line in the Excel Document (the Header) is now located here as variables. Each number in the Variable view indicates a different variable and column in the Data View and in the Data View shows up as the top header for each column. Note that SPSS scans all of your data and can pre-determine the type of data and what the measures are.

10 Recoding Variables Why do we recode variables? Makes working with data easier Numbers are easier to manipulate Can t run powerful analysis with words Recode into Same Variable New information is written over top of what is currently displayed and erases the previous information Recode into Different Variable New information is displayed in a new column at the end of all of the column variables already there and the original variable is still there

11 Recoding Variables Select a variable Rename this variable to distinguish between the 1 st variable 1) Transform 2) Recode into different Variables 3) Select variable to recode 4) Click on the Arrow 5) Rename the variable (i.e. Variable_RECODE) 6) Press Old and New Values

12 Recoding Variables 1) Into Old Value insert the Current Value you would like changed 2) Into New Value insert the new value you want changed 3) Press the Add button 4) Continue to add additional values until you re done for the variable Continue *** PRESS Continue when completed to take you to the previous screen

13 Practice Recoding Gender Class Standing Living Location Dining Plan Honors Female = 0 Freshman = 1 Brody = 1 Silver = 1 No = 0 Male = 1 Sophomore = 2 East = 2 Gold = 2 Yes = 1 Junior = 3 North = 3 Platinum = 3 Senior = 4 Rivertrail = 4 DineOn50 = 4 South = 5 DineOn Owen = 5 Off Campus = 6 None = 6 Helpful tips: Press Reset every time you recode a different variable Just like in Excel, you can drag columns around to better suit you visually

14 Descriptive Statistics (ANALYZE DESCRPTIVE STATISTICS) **Frequencies The basic information for a variable (number of participant in each category, percentage) Descriptives Min/Max values, N for each variable, Mean **Crosstabs A way to examine the relationship between two variables in a rows and columns format

15 Descriptive Statistics - Frequencies Running frequencies allows us to know how many participants fall into each underlying category in a variable.

16 Descriptive Statistics - Descriptives

17 Descriptive Statistics Crosstabs

18 Splitting & Sorting Cases Splitting & Sorting Cases allows you to obtain information relevant to each group instead of the entire data population visually and when running analysis. Before Splitting the File After Splitting the File

19 Practice Splitting Cases Data Split File Select Compare Groups Move Gender into box to be sorted Analyze Descriptives Frequencies Class Standing & Dining Plans Female Male

20 Selecting Certain Cases All Cases = every N case in the data set is used If condition is satisfied = filter by a variable and a category in the variable (i.e. Dining Plan = 1 Only Silver Meal Plan holders are selected) Random sample of cases = select a percentage of the total N dataset to be analyzed. Based on time/case range = Select a range of participants by case number Use filter Variable = select a variable (i.e. Honors selects only those who are Honor students) If you only want to have select participants in your SPSS data sheet select this to have the participants copied into a new SPSS document If you want to clear any changes you made when selecting cases, hit Reset to get the whole data set

21 How to make a Graph Graph Chart Builder Ok **Double clicking on the graph once created allows you to edit and format the graph to be more visually appealing.

22 How to make a Graph

23 Questions? Concerns? Want to learn more? Please contact: Jennifer Thach Paul Goldblatt