Various types of designs can be used to provide research investigations in developmental psychology. Among the most popular ones are the longitudinal designs. They are commonly conducted within a particular parcel of children for several years, which allows the researchers to examine the changes and maintain tests at different ages. This design is beneficial as it provides one with the opportunity to follow the life of a child and note all significant changes and factors that influenced them.
The impact of the human factor (all people are different) is reduced as the participants of the research are the same over time. Still, these methods have some disadvantages. The greatest one is the time needed for the studies, as it can extend from a few years to several decades. If a researcher investigates the influence and connection between the vocabulary that a child knows at the age of two and the ability to write when this child is already eight years old, the research will last for six years and then the time for evaluation will be needed. One more thing is the fact that a lot of the participants leave the experiment while it is still in process.
Some of them will move to distant locations, others will just change their mind and refuse to continue. However, will not be a problem if the researcher is prepared for the high desertion rates from the very beginning. One should recruit many more children than he/she needs to conduct the research. Still, if the discrepancy between those who stay in the program and those who leave it is systematic, the possibility of the biased sample occurs, which is a great drawback (Harris & Westermann, 2015).
Reference
Harris, M., & Westermann, G. (2015). A student’s guide to developmental psychology. New York, NY: Psychology Press.