a good one on chisq

http://faculty.vassar.edu/lowry/ch8pt1.html

Choosing the right test

From the university of Alabama.
http://bama.ua.edu/~jleeper/627/choosestat.html

RECODE in STATA

recode var names (1 2 = 1 low)  ///
                 (3   = 2 medium)  ///
                 (4 5 = 3 high)  ///
                 (nonmissing = 9 "something else")  ///
                 (missing = .)  ///
               , gen(Rx Ry) label(Cat3)

Use mvencode and mvdecode to deal with missing values. 
For example to convert 99 into sysmis
in the variable mstatus,

mvdecode mstatus, mv(99)

For the opposite effect,
mvencode mstatus, mv(99)

Computing Age from DOB in SPSS

There are million ways to do this. but here is what worked for me. You will need your date of birth variable to have month, day and year.

COMPUTE age_year = (DATE.MDY(11,01,2010) - BirthDate) / (60*60*24*365.25) .

COMPUTE age=RND(age_year).
FORMATS age (F3.0).
*fre age.

NOTE: This will create an AGE variable, as of now, not the age of respondent at the time of survey. To do that you would need survey date.

String to Numeric in SPSS

STRING m1 (A10).

execute.

compute m1 = substr(query_co,1,1).

execute.

list m1.