What Is the Role of the Longitudinal Research Approach in Dissertation?

Longitudinal Research Approach

A longitudinal study, also known as a longitudinal survey, is one of the research approaches used in dissertations. In this type of research, researchers collect the same data multiple times at different time points. A longitudinal study’s goal is to determine not simply what the data shows at a specific end of time but also how and why things change over time. The longitudinal research approach examines the same people over time to observe any changes.

The longitudinal research approach is a sort of correlational research. Researchers watch and gather data based on various factors without manipulating them. Longitudinal studies are common in medicine, economics and epidemiology. These studies are also utilised in other social and medical sciences.

Definition of Longitudinal Research

In a longitudinal research approach, the researcher measures the characteristics of the same people on multiple occasions of the time. Its goal is to inspect the individual changes and variations in behaviour over time. Longitudinal studies are more time and money intensive than cross-sectional research. But longitudinal research approach has a lot of significant advantages. Longitudinal studies are critical for understanding developmental and ageing-related changes. Also, these studies are pertinent in evaluating individual differences.

Example of Longitudinal Research Approach

Researchers usually choose individuals who are distinct from other observable variables but comparable in one: drinking. This approach enables the researchers to learn how drinking affects the development of liver disorders later in life. In this example, researchers would study volunteers who began drinking as adults and progressed through life. They will look for changes in their bodies due to their drinking habits.

They can see how drinking has affected participants’ immunity and stress reactions. Researchers will also analyse other variables that are important to the study. Researchers can track the consequences of quitting drinking over time if any participants decide to stop drinking later in life. This approach can aid academics in better understanding the relationship between health and drinking. However, they can buy dissertations online in case of any issue.

Advantages of Longitudinal research approach

The longitudinal research approach has the following advantages:

a) A Better Understanding of Cause and Effect

Researchers can track their subjects in real-time via longitudinal investigations. As a result, researchers can better determine the right order of events. It gives them a greater understanding of causal relationships.

b) Identification of Patterns

The longitudinal research approach helps in identifying patterns in the collected data. In this research, researchers collect data from the same number of respondents multiple times. Consequently, it allows the researchers to spot emergent in real-time.

c) Authenticity

The validity of longitudinal studies is higher. It is because the researcher defines the objectives and rules of the survey before collecting the data.

d) Eliminates Recall Bias

Longitudinal studies have a lesser risk of recollection bias since they record current data at numerous periods in time. In other words, when people are only asked to discuss current events, there is a decreased probability that they will forget an event or key information about it.

e) Adaptability

In longitudinal research, the variables can vary with time. Despite initial assumptions, while collecting data, a researcher might come across new data points or relationships worth investigating.

Disadvantages of Longitudinal research approach

a) Costly and Time-Consuming

Data collection for longitudinal studies suffers takes a significant amount of time. Longitudinal research can take months or years to perform, making it costly and time-intensive. As a result, researchers often have trouble recruiting participants. It leads to reduced sample sizes.

b) Biasness in Data

The researcher collects data at multiple points in this kind of study. The researcher cannot pre-determine the observation period. Also, the researcher cannot possibly consider what occurs between these points. Apart from that, respondents may adjust their qualitative responses over time to better suit what they perceive to be the observer’s goal. The process utilised in longitudinal research alters how respondents and subjects respond to the questions.

c) Participants may drop out of the study.

Longitudinal studies are time-intensive, due to which participants may abandon or drop out of studies for a variety of reasons. They can drop out due to illness, relocation or a lack of ambition to finish the entire examination. Selective attrition is a tendency that can jeopardise the validity of an experiment. As a result, researchers who use this method often recruit many participants. They start the research with the expectation that a significant percentage of people may drop out before they finish.

Types of Longitudinal Studies

Following are the three main types of longitudinal studies:

  1. Panel Study
  2. Retrospective Study
  3. Cohort Study

1. Panel Study

The term ‘panel study’ refers to the recurrent observation of a set of fixed entities at specified intervals. The entities can be people, firms, and nation-states. These studies track people’s actions through time. Researchers focus on people’s thoughts, sentiments and emotions. A panel study is a sort of future research. There are various types of panel studies such as:

  • Consumer panels: They are employed in market research to track purchase and consumption habits changes in connection to a specific product.
  • Household Panel Studies: Household panel studies are the most representative and prospective surveys. These studies are based on a random sample of individuals/households and seek to learn what happens/has happened to the same subjects over time.

2. Cohort Study

Cohort analyses are similar to panel studies in that they interview the same people over time. But in cohort studies, only a random sample of people who had similar life events within the same time range is studied over time. Typically, a researcher may select one or more birth cohorts and deliver a questionnaire to a sample picked from within that group. Cohort studies analyse several generations over time throughout their lives.

3. Retrospective Study

In retrospective studies, researchers ask the interviewees to recall and reconstruct events and elements of their own lives. Typically, the researcher conducts a retrospective study domain by domain. The researcher starts with the current condition and goes backwards with the respondents. The duration or event data is frequently obtained retrospectively through life history studies. Life history studies normally cover an individual’s life span through event histories. The data can be gathered using both prospective panels and cohort studies.


Even though the longitudinal research approach is more costly and time-consuming, it is beneficial to identify the causal relationships in data. You can use this approach to examine events’ progression and how things/phenomena change over time.


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