Control

Logic















Step 1: Selecting participants--How?

Step 2: Assigning Participants to groups--How?

Experimental Control
S1 S5
S2 S6
S3 S7
S4 S8










Experimental Control
M M
M M
W M
W M








Experimental Control
M M
M M
W M
W M




3. Counterbalancing=balancing of the order of treatment conditions

S1:Treatment 1 Treatment 2 Treatment 3
S2: Treatment 2 Treatment 3 Treatment 1
S3: Treatment 3 Treatment 2 Treatment 1














Experimental Control
M1st W1st
W2nd M2nd
W3rd M3rd
Wth M4th






4. Random Assignment









Step 3: Design of Experiment

Recall:
Experimental


"Posttest only control group design"

Experimental Control








Problems:

a. did randomization really work?





"Pretest-Posttest control group design"

Experimental Control












Problems:

a. demand characteristics?



"Solomon 4 group design"
Experimental Control
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