Observational Study – Guide & Example

Time to read: 5 Minutes

An observational study is used to draw conclusions from a target sample purely by observations. Researchers do not alter variables or conditions in an observational study and only record observable characteristics.1

Observational Study – In a Nutshell

  • The observational study looks at elements in their natural environment.
  • Researchers use observational methods to study subjects within a specific time frame.
  • It is an appropriate method of study where there are logistical or ethical concerns in using other research methods.

Definition: Observational study

An observational study refers to a research methodology where researchers only consider the observable variables in a study. No attempt is made to control or set any conditions to influence the study’s findings.

The types of observation used in an observational study

There are several types of observation in observational studies. They can be classified as follows:

Type Description Example
Naturalistic observation It entails studying objects in their natural environment without interference Observing animals in a game park
Participant observation The researcher is part of the day-to-day life of the research participants Living in a community with the participants
Systematic observation It’s a precise list of actions and methodology to be used in studying specific variables A patient’s behavior can be monitored using tests, interviews, tasks, and other tools
Covert observation The participants don’t know they are being observed Observing and interacting with shoppers at a mall
Quantitative observation Uses statistical and numerical tools and methods to measure quantifiable variables Calculating the average income of people in their 30s in a city
Qualitative observation Data is collected through the 5 senses – sight, smell, taste, hearing, and touch Observing the taste of food, the texture of a fabric
Case study It is an intensive focus on a single group or unit Observing students in their final semester in school
Archival research It involves using information from original archives and repositories Reviewing government birth records

Observational study types

Observational studies are used in different research contexts. Researchers can observe different characteristics using the following types of observational studies:

Case-control observation

This type of study uses two groups. One group has an additional variable that is absent from the other. Researchers carry out case-control observations to measure the effect of the variable on an outcome.2

Cohort observation

Cohort studies track participants over time. They are primarily used to observe a population with common characteristics. For instance, cohort studies can be used in studying people in a given occupation or the inhabitants of a place.3

Cross-sectional observation

It focuses on a set of variables at a specific time. Researchers use cross-sectional analysis to analyze themes that occur in a single instance.4

An Observational Study Step by Step

The scope of an observational study spans the elements of data collection and selecting the right population. You can use the following steps:

Step 1: Establish the research question and goals

Defining your research problem entails identifying the methods of observation to be used. It may involve the following:

  • Why are you interested in observing a group?
  • What is the scope of your observation?
  • What ethical concerns may affect your study?

Step 2: Determine the observation type and technique

You may consider the following in choosing your technique:

  • Do you have a pre-selected observation, or will you formulate it as you go along?
  • Can you use another research method in your observational study?
  • What is the effect of doing a covert observation versus notifying the participants?
  • How can you prevent confounding variables that may affect your analysis?

Step 3: Set up and conduct the observational study

Here are a few pointers before you begin your observational study:

  1. Have a plan
    • Work out the details of the nature of the research and know your facilitators. Some establishments have restricted access and may only permit a brief survey.
  2. Consider your note-taking tools
    • Observational study cases often record data through note-taking. Other methods, such as recording devices, may impact the analysis, as some people may shy away from them.
  3. Seek informed permission
    • If you intend to use devices such as video recorders, seek consent first.5

Step 4: Analyzing the results

The methods used to analyze, depend on the nature of the observational study.

You could use an inductive approach if your observation was done in an open-ended manner.

A deductive approach is more suitable when there are established hypotheses before the study.

An in-depth example of an observational study

You may want to study the customer habits of a brand. You can observe the following variables:

  • How much time customers spend at a store.
  • Online ratings of the store.
  • Ages of the people who shop there.

You can decide on one characteristic that you want to study. For example, how much time do buying customers spend at the store? With this research question, you can choose the cohort observation type as your population has a common characteristic. You can check the ratings to identify what customers like and dislike. You may also engage the staff of the store in the study.

Advantages and disadvantages of an observational study

Observational studies are used because they have several benefits. However, like other research methods, they have some drawbacks.


  • It is one of the easiest methods of study.
  • It is carried out in natural surroundings where no variables are influenced, making it a reliable method.
  • It is the most appropriate method for specific subjects.
  • It offers accurate data as the researcher is present in the research environment.
  • It can easily be coordinated with minimal effort or resources.


  • It is impossible to observe everything. A researcher can only observe and record a few things simultaneously, and other variables may go unnoticed.
  • It can be time-consuming since the methodology uses simple tools that cannot accumulate a lot of data in a short time.
  • It does not take into account past events. An observational study is tied to the present, and past factors are not accounted for.
  • The risk of bias. The results of the observational study are subject to the view and interpretation of the researcher. Some thoughts may be influenced by personal biases.6


Observing workers in a factory. The subjects are observed in their natural state as they work and interact with their colleagues. A covert approach may be used where the observations are made without the workers’ knowledge.

We use observational methods where the variable under investigation can be observed and recorded in real time. Researchers also employ observation techniques in cases where other research methods are unusable.7

A cohort observation is a research method where a group with a similar trait is studied. Researchers may use such a sample to study phenomena unique to such groups.

A control group is a group of people exempted from a research condition. They are used to test the effect of the condition on another group in observational research.


1 Science Direct. “Observational Study.” Accessed September, 26, 2022. https://www.sciencedirect.com/topics/medicine-and-dentistry/observational-study.

2 National Cancer Institute. “case-control study.” Accessed on September 26, 2022. https://www.cancer.gov/publications/dictionaries/cancer-terms/def/case-control-study.

3 BMJ Journals. “What are cohort studies?.” Accessed on September 26, 2022. https://ebn.bmj.com/content/22/4/95.

4 Question Pro. “Cross-Sectional Study: What it is + Free Examples.” Accessed on September 26, 2022. https://www.questionpro.com/blog/cross-sectional-study/.

5 Delve. “What is observational research?.” Accessed on September 26, 2022. https://delvetool.com/blog/observation.

6 AplusTopper. “Advantages and Disadvantages of Observation Method | Merits and Demerits of Observation in Marketing.” Accessed on September 26, 2022. https://www.aplustopper.com/advantages-and-disadvantages-of-observation-method/.

7 MRC Clinical Trials Unit. “What is an observational study?.” December 18, 2018. https://www.mrcctu.ucl.ac.uk/patients-public/about-clinical-trials/what-is-an-observational-study/.