SCRAED SIMPLE AND COMPLEX RANDOM ASSIGNMENT IN EXPERIMENTAL DESIGNS 
Valentim Rodrigues Alferes, University of Coimbra (Portugal), 2009 

Last
Modified: NOV092009 SCRAED is a package of 37
selfcontained SPSS syntax files that performs simple and complex random
assignment in experimental designs. 

For betweensubjects designs, SCRAED includes simple random
assignment (no restrictions, forced equal sizes, forced unequal sizes, and
unequal probabilities), block random assignment (simple and generalized
blocks), and stratified random assignment (no restrictions, forced equal
sizes, forced unequal sizes, and unequal probabilities). For withinsubjects or
repeated measures designs, SCRAED
includes complete counterbalancing, partial counterbalancing (Latin squares),
carryover designs (single and double), truncated counterbalancing, and random
ordering of treatments. SCRAED also includes complete documentation
and several randomization tools (e.g., syntaxes for generating tables of
random numbers or random permutations of n
integers), namely ChooseRMD.sps,
an SPSS syntax file for choosing a convenient repeated measures design and
the correspondent SCRAED subprogram. You can run the syntaxes from
this web site, provided you have SPSS installed in your computer.
Alternatively, you can download a compressed file containing all programs and
documentation. DOWNLOAD
ALL PROGRAMS AND DOCUMENTATION [Compressed File 940KB] 





Simple Random Assignment 



SimpleRand1.sps
Equal probabilities 



SimpleRand2.sps
Forced equal sizes 



SimpleRand3.sps
Forced unequal sizes 



SimpleRand4.sps
Unequal probabilities 


Block Random Assignment 



BlockRand.sps
Simple and generalized block designs 


Stratified Random Assignment 



StrataRand1.sps
No restrictions 



StrataRand2.sps
Forced equal sizes 



StrataRand3.sps
Forced unequal sizes 



StrataRand4.sps
Unequal probabilities 







WITHINSUBJECTS
DESIGNS (Repeated Measures Designs) 


ChooseRMD.sps
Choosing a convenient repeated measures design and an SCRAED program 


Complete Counterbalancing 



CC2.sps
2 treatments /2 sequences 



CC3.sps
3 treatments /6 sequences 



CC4.sps
4 treatments /24 sequences 



CC5.sps
5 treatments /120 sequences 



CC6.sps
6 treatments /720 sequences 


Partial
Counterbalancing (Latin Squares) See Standard Latin Squares 


LS2.sps
2 treatments /2 sequences (Identical to CC2 [n per seq.=1] ) 


LS3.sps
3 treatments /3 sequences 


LS4.sps
4 treatments /4 sequences 


LS5.sps
5 treatments /5 sequences 


LS6.sps
6 treatments /6 sequences 


LS7.sps
7 treatments /7 sequences 


LS8.sps
8 treatments /8 sequences 


LS9.sps
9 treatments /9 sequences 


LS10.sps
10 treatments /10 sequences 


LS11.sps
11 treatments /11 sequences 


LS12.sps
12 treatments /12 sequences 


CO2.sps
2 treatments /2 sequences (Single carryover design: Identical to CC2 [n per seq.=1] and LS2) 


CO3.sps
3 treatments /6 sequences (Double carryover design: Identical to CC3 [n per seq.=1]) 


CO4.sps
4 treatments /4 sequences (Single carryover design) 


CO5.sps
5 treatments /10 sequences (Double carryover design) 


CO6.sps
6 treatments /6 sequences (Single carryover design) 


CO7.sps
7 treatments /14 sequences (Double carryover design) 


CO8.sps
8 treatments /8 sequences (Single carryover design) 


CO9.sps
9 treatments /18 sequences (Double carryover design) 


CO10.sps
10 treatments /10 sequences (Single carryover design) 


CO11.sps
11 treatments /22 sequences (Double carryover design) 


CO12.sps
12 treatments /12 sequences (Single carryover design) 

Truncated
Counterbalancing and Random Ordering of Treatments 










RANDOMIZATION
TOOLS 



TableRN.sps Generating a table of random
numbers 



PerInt.sps
Generating a random permutation of n
integers 



PerObj.sps
Generating a random permutation of n
objects 



Buzz phrase generators: BuzzClassic.sps BuzzEconomy.sps BuzzHealth.sps 




REFERENCES 

Alferes, V. R. (1997). Investigaηγo cientνfica em psicologia:
Teoria e prαtica [Scientific research
in psychology: Theory and practice]. APA
Publications and Communications Board Working Group on Journal Article
Reporting Standards. (2008). Reporting standards for research in psychology:
Why do we need them? What might they be? American
Psychologist, 63, 839851. doi:
10.1037/0003066X.63.9.839 Cochran,
W. G., & Cox, G. M. (1957). Experimental
designs (2nd ed.). Kiess,
H. O., & Bloomquist, D. W. (1985). Psychological research methods: A
conceptual approach. Kirk, R. E.
(1995). Experimental design: Procedures
for the behavioral sciences (3rd ed.). Maxweel, S.
E., & Delaney, H. D. (2004). Designing
experiments and analysing data (2nd ed.). Neter, J.,
Wasserman, W., & Kutner, M. H. (1985). Applied linear statistical models: Regression, analysis of variance
and experimental designs (2nd ed.). Shadish, W. R., CooK, T.
D., & Campbell, D. T. (2002). Experimental
and quasiexperimental designs for generalized causal inference. Winer, B. J.,
Brown, D. R., & Michels, K. M. (1991). Statistical principles in experimental design (3rd ed.). 



Suggested Citation 

Generic Alferes, V. R. (2009). SCRAED: Simple and
complex random assignment in experimental designs [SPSS Syntax Files].
Retrieved from /niips/spss_prc/scra/scra.htm Specific program (example: StrataRand2.sps
Forced equal sizes) Alferes, V. R. (2009). Simple and complex
random assignment in experimental designs:
StrataRand2.sps
Stratified random assignment [SPSS Syntax File]. Retrieved from /niips/spss_prc/scra/scra.htm 

