Consecutive sampling, also known as total enumerative sampling, is a non-probability sampling technique used in the design of experiments and research methodology. In this method, every subject who meets the predefined criteria of inclusion is selected for the study, in the order in which they become available, until the required sample size is achieved.
Overview
Consecutive sampling is one of the most commonly used forms of non-probability sampling, alongside convenience sampling and snowball sampling. The defining characteristic of this technique is that the researcher enrolls all eligible subjects who present themselves during the data collection period, rather than selecting a random subset. This sequential recruitment continues until a predetermined sample size or time limit is reached.
Relationship to Other Sampling Methods
Consecutive sampling is closely related to convenience sampling, as both rely on the availability and accessibility of subjects rather than random selection. However, consecutive sampling is generally considered superior to convenience sampling in controlling sampling bias, because it includes every eligible subject rather than allowing the researcher to choose which subjects to include. This reduces the potential for researcher-driven selection bias.
Advantages
- Reduced selection bias compared to convenience sampling, since all eligible subjects are included.
- Practical and efficient for studies where the target population is accessible over a defined period.
- Useful in clinical and applied research settings, where patients or participants present sequentially and enrolling all eligible cases is feasible.
Limitations and Considerations
- Temporal or seasonal trends: If the quantity of interest varies over time or by season, consecutive sampling may produce results that are not representative of the broader population.
- Common similarity among consecutive samples: Bias can occur when consecutive samples share common characteristics, such as consecutive houses on the same street, which may not represent the wider population.
- Non-probability nature: Because subjects are not randomly selected, the sample may not be statistically representative, limiting the generalizability of findings.
Applications
Consecutive sampling is frequently employed in clinical research, epidemiology, nursing research, and other applied fields where researchers need to recruit participants who meet specific inclusion criteria as they become available. It is particularly useful when other sampling methods are impractical or unavailable.
References
- Suresh, K., & Sharma, S. (2014). Nursing Research and Statistics. Elsevier Health Sciences.
- Schuster, D. P., & Powers, W. J. (2011). Translational and Experimental Clinical Research. John Wiley & Sons.
- Van den Broeck, J., & Brestoff, J. R. (2013). Epidemiology: Principles and Practical Guidelines. Springer Science & Business Media.
- Polit, D. F., & Beck, C. T. (2010). Essentials of Nursing Research: Appraising Evidence for Nursing Practice. Lippincott Williams & Wilkins.
- Indrayan, A., & Holt, M. P. (2016). Concise Encyclopedia of Biostatistics for Medical Professionals. CRC Press.
