Which of the following are quasi-experimental designs?
(1) Interrupted Time-Series Designs
(2) Non-equivalent Control Group Design
(3) Time Series with Non-equivalent Control
(4) Block randomization

Correct option is C

Options 1, 2, and 3 are all quasi-experimental designs that lack random assignment but attempt to establish causal relationships. Block randomization (4) is a true experimental design technique, not a quasi-experimental design.

Information Booster:
• Quasi-experimental designs are used when random assignment is not feasible due to ethical, practical, or logistical constraints
• Interrupted Time-Series Design involves multiple measurements before and after an intervention without random assignment
• Non-equivalent Control Group Design compares naturally occurring groups (not randomly assigned) with one receiving treatment
• Time Series with Non-equivalent Control combines time-series measurements with a comparison group that wasn't randomly assigned
• Quasi-experiments have higher external validity than lab experiments but lower internal validity than true experiments
• These designs are commonly used in educational, clinical, and policy research where randomization is impossible