Pre-Experimental Designs

 1.  One-Shot Case Study

        X  O
 
 2.  One-Group Pretest-Posttest Design

        O1  X  O2
 
 3.  Static-Group Comparison or Intact-Group Comparison

        X   O1    or   X1   O1
        ------         -------
            O2         X2   O2
 
True Experimental Designs
 
 4.  Pretest-Posttest Control Group Design

        R  O1  X  O2   or  R  O1  X1  O2
        R  O3     O4       R  O3  X2  O4
        
        which can easily be extended to
        
        R  O1  X1  O2
        R  O3  X2  O4
        R  O5  X3  O6
        R  O7  X4  O8       
         
 5.  Posttest-Only Control Group Design

        R  X  O1    or    R  X1  O1
        R     O2          R  X2  O2
        
        which can easily be extended to
        
        R  X1  O1
        R  X2  O2
        R  X3  O3
        R  X4  O4
 
 6.  Solomon Four-Group Design

        R  O1  X  O2    or    R  O1  X1  O2
        R  O3     O4          R  O3  X2  O4
        R      X  O5          R      X1  O5
        R         O6          R      X2  O6
 
Quasi-Experimental Designs

 7.  Nonequivalent Control Group Design

        O1  X  O2          O1  X1  O2
        ---------    or    ----------
        O3     O4          O3  X2  O4
 

 8.  Time-Series Experiment

        O1  O2  O3  O4  X  O5  O6  O7  O8
        
        examples:
        
 
 9.  Equivalent Time-Sample Design

        X1 O   X2 O   X1 O   X2 O  
        
        example:
        
 
10.  Counterbalanced Designs

        Group A  X1 O  X2 O  X3 O
        -------------------------
        Group B  X3 O  X1 O  X2 O 
        -------------------------
        Group C  X2 O  X3 O  X1 O
 
11.  Separate-Sample Pretest-Posttest Design

        R  O
        R     X  O
 
12.  Separate-Sample Pretest-Posttest Control Group Design

        R  O
        R     X  O
        ----------
        R  O
        R        O
 
13.  Multiple Time-Series Design

         O  O  O  O  X  O  O  O  O         O  O  O  O  X1  O  O  O  O
         -------------------------    or   -------------------------- 
         O  O  O  O     O  O  O  O         O  O  O  O  xX  O  O  O  O

          
X  ->  A treatment 
O  ->  An Observation
R  ->  Random assignment to groups 
-- ->  Intact groups        
 

Adapted from: Campbell, Donald T. & Stanley, Julian C. (1963). Experimental and quasi-experimental designs for research. Chicago: Rand McNally & Company.

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