One of the core methods used to structure scientific articles is OCAR – an acronym that stands for Opening, Challenge, Action, and Resolution. It provides a clear and logical framework for presenting your research, helping to ensure readers understand and appreciate your work.

An easy way to think about OCAR is to think of a fairytale. For example, a princess lives in a kingdom but is confined to the castle and is unhappy (opening). One day she escapes. While walking, she is kidnapped by a dragon (challenge). A knight comes to save her, killing the dragon and rescuing the princess (action). They get married and live happily ever after (resolution).

Ocar – Opening

The O in OCAR stands for opening. The opening of your scientific article is essentially the introduction. Just like in our fairytale above, it sets the stage by providing context and background information, presenting the problem or issue you intend to address.

A good opening should clearly define what the article is about, frame the problem, and introduce the critical elements under discussion later in the article. Consider your audience: for specialists, a brief introduction may suffice, while generalists might require more extensive background information.

You can read in more detail about the opening, how it works and how to write one here.

oCar – Challenge

The challenge is the part of your article where your research starts to show. For the princess, her challenge was her kidnapping.

For you, it is your hypothesis or research question. This could be an assertion like “Hummingbirds prefer red flowers” or a question such as “What is the rate constant for a chemical reaction involving methane and hydroxyl radicals?” It’s crucial to focus on the question or hypothesis rather than the objective. The challenge section should clearly outline what you hope to discover or confirm through research.

You can read in more detail about the challenge, how it works and how to write one here.

ocAr – Action

The action is what is done to overcome the challenge. In our fairytale, the actor is a knight who kills the dragon. For us, it refers to the meat of your research – the methods you used to investigate your hypothesis and the results you obtained. Here, it’s often beneficial to use an LD (Launch-Development)/point-first structure where you first give an overview of what you did or found, and then delve into the specifics. Make sure to distinguish between your data, inferences, and interpretations.

You can read in more detail about the action, how it works and how to write one here.

ocaR – Resolution

Finally, the resolution in our fairytale is that the princess lives happily ever after. In science, it is where we summarise our findings and interpret their significance about the problem introduced in the opening. This could include discussing the implications of your research, suggesting future work, or posing new questions. Your resolution should provide a succinct wrap-up of your work, reminding readers of the problem and how your research contributes to solving it.

You can read in more detail about the resolution, how it works and how to write one here.

Click here to read more about structuring articles.

Interested in learning more about Scientific English? You can read a brief post on the History and Use of Scientific English here. More posts on Scientific English are available on the Scientific English page.