Final answer:
Using a Psychology Department's subject pool for a study constitutes a convenience sample, which is practical but may be biased. Random sampling methods, which include simple random, stratified, cluster, and systematic sampling, provide each individual an equal chance of being chosen, enhancing representativeness.
Step-by-step explanation:
When college students from a Psychology Department's "subject pool" are used in a study, the type of sampling being used is a convenience sample. This nonrandom sampling technique is often chosen because it is practical and the subjects are easily accessible to the researcher.
However, the convenience sample may not fully represent the population, which can lead to biased data. Random sampling methods, such as simple random sampling, stratified sampling, cluster sampling, and systematic sampling, offer each individual in the population an equal chance of being included, thus helping to ensure a more representative sample.
For instance:
- If a soccer coach selects players based on age groups to form a team, this is an example of stratified sampling.
- Surveying all human resource personnel in a selected number of companies is an example of cluster sampling.
- Choosing an equal number of male and female teachers for research from a high school uses stratified sampling.
- An instructor sampling students across different math classes by randomly selecting a few from each class is employing stratified sampling.
- When interviewing all employees in a few randomly chosen departments of a store, the method is cluster sampling.
Choosing a random sample is effective because everyone has the same chance of being part of the study, thus minimizing selection bias.