Cross-Sectional and Longitudinal Study

Research or study techniques vary on a person's interest, requirements, and aim of the project. Before developing any project, you need to decide on certain parameters that how would you collect your data and analyze it. We decide what data samples we need to collect based on:

• Segment
• Period
• Location

In doing research, we also have to decide what subjects we should consider and what information or knowledge we should gain from them. These types of studies are:

• Probability and Non-Probability Sampling
• Cross-Sectional and Longitudinal Study
• Field Research and Laboratory Research

A person needs to research or study depending on the project requirement. In this article, we will be discussing Cross-Sectional and Longitudinal Studies.

Cross-Sectional Study

• In this study, we study individuals from different segments or samples at a single point in time (Same Period).
• This study aims to examine the correlation between variables of interest. It involves the analysis of multiple variables of different individuals at a single point in time. The researcher cannot change or manipulate any existing variable. Hence this is used for only observational studies.
• In this study, we cannot determine the cause-and-effect relation. This study does not consider data before or after that particular time.
• It allows researchers to analyze several factors at once and provide information regarding the activities going on in a population.
• This study is usually inexpensive and faster to execute since we are collecting data for a single point of time only.
• Since we only consider a single point of time, hence we cannot generate longer trends and analyze behavior over a period of time. Because of this, it would be difficult to generate an inference and speculations.
• Types:

1. Descriptive
2. Analytical

Example

Understand the relationship between smoking and heart disease. For this, we would require persons of different age groups with data points like age, gender, sugar level, cholesterol level, location, etc. Then we will derive the correlation among variables of interest and generate insights and detailed descriptive analysis.

Longitudinal Study

• In this study, we study the same individuals over a period of time. We usually collect and analyze data from the same individuals we selected at the start over a different period of time.
• In this, we study the change in behavior and the effect of time on the variables that we selected. The aim is to observe the change in variables over time.
• There is no limit to the time in this study as it can take place for days, weeks, months, or years.
• It is also considered a type of correlational study in which looks at the correlation or relationship between 2 or more variables.
• Types:

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

• Unlike the Cross-Sectional study, we can generate a cause-and-effect relationship in this study since we are capturing subjects over a longer period of time.
• It also overcomes the issue of recall bias in which the researcher is not able to recall the subject past events. Also, this study is expensive, time-consuming, and requires significant resources.

Example

• Analyzing the company share price trend
• Analyzing the product/app reviews
• User engagement and behavior on the app
• Understanding the relationship between customer behavior and churn