Question

A researcher plans to study the long-term effect of Covid-19 on human cognitive functions. The plan is summarized below.
STUDY-I (Study conducted in 2022)
Group A: 10 years old males and females
Group B: 20 years old males and females
Group C: 30 years old males and females
STUDY-II (Study to be conducted in 2025)
Group D: 13 years old males and females
Group E: 23 years old males and females
Group F: 33 years old males and females
This research design is known as?

• A. Cross-sectional design
• B. Longitudinal design
• C. Cross-sequential design
• D. Long-term design

Hint:

Remember: Cross-sequential studies combine the "snapshot" perspective of cross-sectional designs with the developmental insight of longitudinal designs. This hybrid approach offers a powerful way to study change across age and time.

Answer 1

The Correct Option is C

Step 1: Define the major designs.
- Cross-sectional design: Compares different age groups at one point in time; quick but vulnerable to cohort effects.
- Longitudinal design: Follows the same individuals (or cohort) over a prolonged period; controls for individual differences but can be time-consuming and suffer from attrition.
- Cross-sequential design: Integrates both approaches by studying multiple cohorts over time, allowing researchers to disentangle age, period, and cohort effects.
Step 2: Apply to the study plan.
In 2022, the researcher measures three distinct age-based cohorts (10, 20, and 30-year-olds). In 2025, the same participants are re-assessed three years later (now 13, 23, and 33 years old). This procedure tracks multiple cohorts longitudinally while retaining the cross-sectional comparison across ages.
Step 3: Why it's cross-sequential.
- Cohort tracking: Each group (A→D, B→E, C→F) represents the same individuals tested at two time points.
- Cross-sectional comparison: At each measurement, the study includes different age cohorts, enabling age-based comparisons.
Step 4: Advantages and considerations.
- Controls for both age effects and cohort effects, enhancing internal validity.
- More efficient than a pure longitudinal study, since intervals are shorter and multiple cohorts provide broader context.
- Requires careful planning to manage participant retention across time points.