Quasi-Experimental Designs

Know Your Notation

100

O₁ O₂ O₃ O₄ X O₅ O₆ O₇ O₈

Time-Series Design

200

M_aX₁O  M_bX₀O  M_cX₁O  M_dX₀O

Equivalent Materials Design

300

X₁ O X₀ O X₁ O X₀ O

Equivalent Time-Samples Design

True or False?

100

Matching is implemented for the same purpose in both pretest-posttest control group designs and nonequivalent control group designs.

False

200

It is vital for experimenters using a time-series design to specify when they expect a treatment effect to manifest.

True

300

It's important to switch instrumentation in the middle of a time-series if it is found to be outdated, even if it needs to be changed at the same time as the treatment is introduced.

False

Threats to Validity

100

Experimental designs in which the same participants experience multiple treatments possess this threat to external validity.

Multiple-treatment interference

200

Time-series designs are susceptible to this threat to internal validity, one that Campbell and Stanley say is the counterpart to 'experimental isolation' in the physical sciences.

History

300

Nonequivalent control group designs generally have strong internal validity, but uncommon scenarios can cause this threat to internal validity.

Interaction of Selection and Maturation