1 Using the Syntax window AKA Learning a new language!

2 Why use syntax? To keep a record of computations & analyses –They can get to be too many to recall (esp.. if you are doing ‘exploratory’ analyses) –One may end of redoing analyses them OR –Do analyses differently when redoing them which can cause different & confusing results

3 What is a syntax window? Allows you to type in the modifications of the variables you have Allows you to type/paste in the analyses you like to conduct

4 Syntax in EXCEL Syntax in SPSS Compute lifesat =mean(item1, item2, item3).

5 What we did so far…what’s next What is syntax Why do syntax How is syntax done in SPSS vs EXCEL

6 Example of Syntax in EXCEL Example of Syntax in SPSS Compute lifesat =mean(item1, item2, item3).

7 Features of Syntax in Excel In EXCEL you type/paste syntax in the function box

8 Features of a syntax window in SPSS In SPSS you type/paste functions in a separate window/file which takes the extension.sps (cf..doc,.ppt) See next slide for example of the window

9 The syntax window in SPSS

10 Syntax in SPSS vs EXCEL Done in the same ‘location’ in EXCEL (i.e., in function box) above the data Can also be done in the same location in SPSS, But SPSS provides a “shortcut” for some types of syntax… Analyses syntax Computations syntax

11 What are Analyses & Computations Computations –e.g., recoding variables; or creating new variables means of items Analyses –e.g., correlations, reliabilities, frequencies, means etc. YOU ALREADY KNOW THIS! Note means of items are different from means in the sample…more later…

12 Generate syntax for analyses in SPSS Download & open the student satisfaction survey data Go to the correlational analyses window, pick the two variables you want to correlate Then click on ‘paste’ when in correlational analysis menu Go to the syntax window –Click under window on top right

13 Students work on their own & do correlational analyses for any two variables in the and generate syntax

14 Screen you should be at when you successfully paste the correlational Analyses from the Data Window into the Syntax window

15 Students continue working in syntax window… Select the analyses pasted in the syntax window Click on RUN button on top right

16 What we did so far…what’s next What is syntax Why do syntax How is syntax done in SPSS vs EXCEL –Syntax in SPSS is different for Analyses vs. Computations –Syntax in EXCEL is same for analyses & computations

17 Syntax for computations in SPSS vs EXCEL In SPSS, you need to open a separate syntax window In EXCEL you can directly start typing your computations in the function window

18 How to open a syntax window

19 Close look at Syntax in EXCEL In the example above –“STDEV” is the type of the function Can be substituted w/mean, sum –“A2: A16” in parenetheses are cell values on which the function is to be performed e.g., the values in cells A2 to A16 should be used to compute the std dev

20 How the Syntax in SPSS differs & is similar to that in EXCEL Compute lifesat =mean(item1, item2, item3). Differences from EXCEL –Comma in between items vs. colon –Period at the end of the statement Similarities w/Excel – Can use ‘sum’ and other operands similarly –Items enclosed in parens after the ‘function’

21 More ‘Rules’ of Syntax in SPSS Compute lifesat =mean(item1, item2, item3). –Lifesat is now new variable you computed in your data –Features of the variable name (e.g., lifesat) is 8 characters or fewer Cannot be the same as the name of another variable already in data set It cannot start with a numeric value

22 What we did so far…what’s next What is syntax Why do syntax How is syntax done in SPSS vs EXCEL –Syntax in SPSS is different for Analyses vs. Computations –Syntax in EXCEL is same for analyses & computations

23 Why use syntax? To keep a record of computations & analyses –They can get to be too many to recall (esp.. if you are doing ‘exploratory’ analyses) –One may end of redoing analyses them OR –Doing analyses differently when redoing them which can cause different & confusing results –Check the accuracy of your analyses

24 Checking the accuracy of your analyses and keeping them consistent across iterations with syntax files e.g., *reverse scoring negatively worded LS items. “*” at beginning and “.” at end enables you to use English to make notes about nature of analyses/computations in syntax files –E.g.,*wage is related to education after controlling for SAT scores. –E.g., *tests hypo that wage is related to education after controlling for GPA -- not supported.

25 Taking advantage of SPSS syntax Being accurate Being consistent Rechecking analyses Keeping records Utilizing multi-item scales

26 Computing multi-item scale scores in SPSS using Syntax Window What is a multi-item scale? Why use a scale score rather than an individual item?

27 Before computing scale scores, first reverse score differently worded items Recode item1 (5=1) (4=2) (2=4) (1=5). Additional things you can do –Can recode multiple items Recode item1 item5 (5=1) (4=2) (2=4) (1=5). –Can use ‘to’ statement for multiple items Recode item1 to item10 (5=1) (4=2) (2=4) (1=5). –If items to be reverse scored are lined up in the data file in that order

28 After reverse scoring, then compute means of items Compute ls =mean(item1, item2, item3). –How is this different from the results you get in “descriptives” analyses and you get the mean of item1? Students do the analyses and orally explain

29 Students Compute scale scores for Global Life Satisfaction (LS) Recode Negatively worded Life Satisfaction items –How can you check you did it correctly? Compute a life Satisfaction scores by taking the mean of all items –Can only do after reverse scoring –Why not take the sum of all items? Advantages vs. disadvantages –What types of things can/should you take sums of?

30 Generalizing what you learned about computations & applying it to statistical analyses

31 Students correlate LS with specific types of satisfaction & stressors Compute reliabilities for each specific type of satisfaction & each type of stress Compute scale scores for each –Ensure you recode appropriately Correlate lifesat with each type of sat & each type of stress

32 Does a stressor in relationship, work, school affect the relevant type of satisfaction which in turn affects life satisfaction? –Do Mediator regression analyses Which type of specific satisfaction best predicts overall life satisfaction –Do Stepwise regression LS, specific types of satisfaction, Stress