A longitudinal research is an observational research method in which information or data is collected for the same subjects over a period of time. They are often used in the field of psychology. Longitudinal researches can take place over a week, month, year or even years. In some cases, it can last to decades.
Just like any other research, longitudinal research also has some advantages and disadvantages. They are;
- Effective in determining variables:- Since, longitudinal studies include collecting information in longer period of time, they are able to determine the patterns efficiently. It is easy for a researcher to know more about causes and effect relationship and make connections in a clear way. These studies are really effective for determining long term changes that have occurred.
- Powerful than cross sectional :- Longitudinal studies are known to be more powerful than cross sectional studies when it comes to excluding time invariants and unobserved individual differences.
- Provide meaningful insights:- Longitudinal studies provide meaningful insights that may not be applicable with other researches such as cross sectional and similar studies. The longitudinal study also help the researcher to trace the development over time rather than directly jumping to conclusions.
- Chronological order of events can be traced:- Longitudinal studies have the ability to identify events. The chronicity of events can be recognized by conducting this type of study especially in the medical field.
- Time consuming:- Longitudinal research requires huge amount of time. It takes considerable amount of time to collect and organize the data. Moreover, it takes equally amount of time to gather the results. By this time, Participants are more likely to drop out as they get bored. There is less chance that all the participants stay until the entire research ends. Continuity of the research is highly affected because of this factor.
- Can be expensive:- One of the main drawback of longitudinal research is that it is not cost effective. The amount of money that needs to be pitched in, is considerably high since longitudinal researches run for a long period of time. Because of this reason, the study consists of small group of people, which makes it difficult to apply the results to a wide population.
- Require large sample size:- Another main drawback of the study is that it requires a large size of sample. The researcher should have a large number cooperating samples otherwise the research will not work perfectly.
- Panel attrition:- If the researcher is only depending on the same group of subjects for a research, then there is high possibility that some of the subjects won’t be able to participate for various reasons, such as variations in the contact information, geographic location or even death.
- Risk of getting unreliable data:- People are likely to behave differently once they know they are being observed. So, it becomes very difficult to obtain unbiased data. The participants might unknowingly change their qualitative responses over time. This can adversely affect the result of the entire research.