In which type of sampling does each individual have a non-equal chance of selection?

The chosen answer is correct because in convenience sampling, individuals are selected based on their availability or ease of access, rather than through a probability-based method. This approach often leads to a scenario where some individuals have a higher likelihood of being included in the sample simply because they are easier to reach. For instance, researchers might survey people in a nearby location or those who are readily available, resulting in a non-random selection process.

In contrast, simple random sampling provides every individual in the target population an equal chance of selection, ensuring that all groups are represented fairly. Similarly, cluster sampling involves dividing the population into clusters and randomly selecting entire clusters, which maintains equal selection chances within the selected clusters. Systematic sampling also affords equal chance of selection by selecting individuals at regular intervals from a randomly ordered list of the population. Therefore, convenience sampling stands out for its inherently biased method of selection where not every individual has the same chance of being included.