Panel Study:
* Definition: A panel study involves repeatedly collecting data from the same individuals at multiple points in time.
* Focus: The focus is on observing changes within individuals over time, understanding how their characteristics and experiences evolve.
* Data Collection: Data is gathered from the same individuals at pre-determined intervals, often using surveys or interviews.
* Example: A study that surveys a group of high school students annually to track their academic performance, attitudes towards education, and career aspirations.
Cohort Study:
* Definition: A cohort study follows a group of individuals who share a common characteristic (e.g., birth year, exposure to a specific event) over time.
* Focus: The focus is on comparing outcomes between different subgroups within the cohort, often to understand the impact of a specific exposure or intervention.
* Data Collection: Data is collected at different points in time, but not necessarily from the same individuals (though it can be). The focus is on comparing the experiences of the cohort as a whole.
* Example: A study that follows all individuals born in a specific year to track their health outcomes over time, comparing the incidence of chronic diseases between those who were exposed to a particular environmental factor and those who were not.
Key Differences:
| Feature | Panel Study | Cohort Study |
|---|---|---|
| Sample | Same individuals across time | Group sharing a common characteristic |
| Focus | Individual changes over time | Group comparisons |
| Data Collection | Repeated measurements from the same individuals | Measurements from different individuals within the group |
| Example | Tracking individual students' academic performance over time | Comparing health outcomes between exposed and unexposed individuals born in a specific year |
In Summary:
Panel studies focus on individual change over time, while cohort studies focus on group comparisons based on shared characteristics. While both are longitudinal studies, they differ in their sample selection and data collection methods.