Original research refers to the creation of new knowledge through the investigation of a topic or problem. This can involve conducting experiments, collecting data, and analyzing results in order to draw conclusions and make new discoveries. On the other hand, secondary research refers to the use of existing sources and information to gather facts about a topic, without producing new knowledge. It relies on the work of others and does not involve original investigation or experimentation. The following are illustrative examples of original research.

Exploratory Research

Research that proposes direction for further research without directly solving a problem. This can include definitions, procedures and framing of questions or thought experiments. For example, a physicist may propose a new way to search for earth-like planets without actually implementing the method due to cost constraints.

Constructive Research

Constructive research builds something that creates new knowledge. For example, a computer scientist who publishes a new algorithm for machine learning.

Controlled Experiments

An experiment that occurs in a controlled environment such as a lab. For example, research to determine the effect of a concentrated plant oil applied in vitro to a virus.

Field Experiment

An experiment in the real world where all variables can’t all be controlled such as an experiment to test different combinations of companion plants for tomatoes that act as a form of pest control.

Natural Experiment

A natural experiment is a situation that researchers have no control over that resembles an experiment. For example, half of the public high schools in a metropolitan area pilot a program for a year that provides nutritious lunches to students free of charge.

Cohort Study

Research that observes or applies an experiment to a group of people who have a shared characteristic. A cohort study is a type of longitudinal study that collects results over a period of time that may extend for months, years or decades. For example, a cohort study based on 5,000 babies all born this year in the same country that collects data related to the conditions of their life and outcomes over the next 50 years.

Retrospective Cohort

A retrospective cohort study selects a group of people based on outcomes and works backwards to collect historical data about them. For example, selecting a cohort of people in their 30s who have severe tooth decay and collecting data about their historical oral hygiene practices and diet.