Longitudinal research is an observational study that collects qualitative and quantitative data and is responsible for using continuous or repeated measures to follow particular individuals over an extended period of time, often years or decades. Longitudinal research definition
In this study, the creator of the survey does not interfere with the respondents who are observed for a period of time ranging from months to decades to verify any changes in them or in their attitude.
For example, a researcher wants to find out which disease affects children ages 10-15, so he will observe individuals during that time period to collect meaningful data.
Unlike longitudinal studies, where research variables may change during its long course of study, a cross-sectional study is carried out in a single instance with all variables remaining the same throughout the study. Longitudinal research definition
Continuing with the previous example, if the cross-sectional study concludes that there is indeed a disease that affects a certain subset of the initial population used for the research, then a longitudinal research can be carried out to investigate the new aspect.
The difference between both studies is the timeline and the variable. In the cross-sectional study, the researcher conducts studies with the same variable and is carried out only once. In longitudinal research, an investigator conducts a study using different variables over a period of time and collects data based on those studies.
Many medical research is longitudinal in nature. Although, it also has a tremendous impact in the business field, as various aspects of the business and the brand can be measured and compared by conducting surveys.
Examples of longitudinal research
Some of the classic examples that can be used for longitudinal studies are:
Market trends and brand awareness: To understand a market trend and brand awareness, market research works wonders. Through these surveys, companies or organizations can find out what customers want and what they discard. This study can be carried out over a period of time to understand market trends as they tend to change constantly. Longitudinal research definition
Feedback on the product: If a company or brand has launched a new product and wants to know what consumers think, opinion polls can be carried out . Comments can be collected over a long period of time. Once the data is collected, companies or brands can put this information into practice.
Customer satisfaction: The customer satisfaction survey helps the organization know the level of satisfaction of its customers for as long as they want. This study can also take years.
Employee engagement : In an organization, management is employee engagement in the workplace is the most important thing. This is an ongoing study in which a survey is conducted to understand the level of engagement, the appropriate feedback is collected, and acted upon.
How to carry out longitudinal research?
Longitudinal research is useful, not only in the field of science and medicine but also in many others. There are many reasons why an investigator might want to conduct a longitudinal study. One of the most important is that they give a unique view that many other types of research fail.
Let’s take an example to understand how to conduct a longitudinal research.
Hypothetically, consider that there is a study done to understand the similarities or differences between identical twins who are raised together versus identical twins who are not raised together on a variety of variables. The researchers, in this case, would like to observe these participants from childhood to adulthood and understand how growing up in a different environment influences traits, habits, and personality. Since the participants share the same genes, any differences are assumed to be due to environmental factors. Longitudinal research definition
Longitudinal research is carried out over a longer period of time ranging from a few years to decades, the data collected can be extremely useful when looking at changes over a period of time. Researchers collect and analyze these inferences.
Another example is that a researcher has been hired to study whether there is a relationship between violence and the use of video games. A sample is collected for the study and to reduce the amount of interference a large group of participants is collected from a population that plays video games. Here the age group is restricted to people between 13 and 19 years old. The next step is to record how violent the sample participants are currently. This creates a baseline for later comparisons. The investigator must keep a record of the number of video games they are playing.
This study can last for months or even years. During this time, the researcher can make before-and-after comparisons of the participants’ behavioral aspects to keep track of whether there is a link between violence and video games. Longitudinal research definition
Types of longitudinal research
There are three main types of longitudinal studies:
Study panel : A study panel is a particular type of longitudinal research in which there is a sample of people from a larger population and is carried out at specific intervals over a longer period of time.
One of the most important characteristics of the panel study is that data is repeatedly collected from the same sample at a different time. Most panel studies are designed for quantitative analysis, however they can also easily be used for qualitative data collection and analysis.
Cohort study : A cohort study is a form of longitudinal research that samples a group of people who typically experienced a common event at one point in time. It is used essentially in the field of medicine.
Some might argue and call clinical trials a form of cohort studies, however there is a mere observation of the sample or the participants involved. Longitudinal research definition
Retrospective study: The retrospective study makes use of existing data because a similar type of research has been carried out previously. When conducting a retrospective study, the researcher uses an existing administrative database, pre-existing medical records, or a personal interview.
- Longitudinal research is used exceptionally because of its ability to identify and relate to events.
- By conducting this type of study, the chronology of events is known, especially in the field of medicine.
- Since the longitudinal study takes place over a long period of time, it helps to identify and establish a particular sequence of events.
- Because this study can last for a period of time, the amount of money that is needed to carry out this study is quite high. Longitudinal research definition
- A long period of time can mean that the number of respondents drop out of the survey. People get bored and will most likely not participate until the end of the research.
- People can start to act differently because they know they are being watched. This is inconvenient in terms of the data collected. It will not remain impartial.
Longitudinal research helps provide meaningful insights that might not be possible with other forms of study, such as cross-sectional studies. Additionally, it allows researchers to track development over a longer period of time, rather than just jumping to conclusions.