At the beginning of the Introduction section, the context and need work together as a funnel: They start broad and progressively narrow down to the issue addressed in the paper. To spark interest among your audience — referees and journal readers alike — provide a compelling motivation for the work presented in your paper: The fact that a phenomenon has never been studied before is not, in and of itself, a reason to study that phenomenon.

Write the context in a way that appeals to a broad range of readers and leads into the need. Do not include context for the sake of including context: Rather, provide only what will help readers better understand the need and, especially, its importance. Consider anchoring the context in time, using phrases such as recently, in the past 10 years, or since the early 1990s. You may also want to anchor your context in space (either geographically or within a given research field).

Convey the need for the work as an opposition between actual and desired situations. Start by stating the actual situation (what we have) as a direct continuation of the context. If you feel you must explain recent achievements in much detail — say, in more than one or two paragraphs — consider moving the details to a section titled State of the art (or something similar) after the Introduction, but do provide a brief idea of the actual situation in the Introduction. Next, state the desired situation (what we want). Emphasize the contrast between the actual and desired situations with such words as but, however, or unfortunately.

One elegant way to express the desired part of the need is to combine it with the task in a single sentence. This sentence expresses first the objective, then the action undertaken to reach this objective, thus creating a strong and elegant connection between need and task. Here are three examples of such a combination:

To confirm this assumption, we studied the effects of a range of inhibitors of connexin channels . . . on . . .

To assess whether such multiple-coil sensors perform better than single-signal ones, we tested two of them — the DuoPXK and the GEMM3 — in a field where . . .

To form a better view of the global distribution and infectiousness of this pathogen, we examined 1645 postmetamorphic and adult amphibians collected from 27 countries between 1984 and 2006 for the presence of . . .

An Introduction is usually clearer and more logical when it separates what the authors have done (the task) from what the paper itself attempts or covers (the object of the document). In other words, the task clarifies your contribution as a scientist, whereas the object of the document prepares readers for the structure of the paper, thus allowing focused or selective reading.

For the task,

• use whoever did the work (normally, you and your colleagues) as the subject of the sentence: we or perhaps the authors;
• use a verb expressing a research action: measured, calculated, etc.;
• set that verb in the past tense.

The three examples below are well-formed tasks.

To confirm this assumption, we studied the effects of a range of inhibitors of connexin channels, such as the connexin mimetic peptides Gap26 and Gap27 and anti-peptide antibodies, on calcium signaling in cardiac cells and HeLa cells expressing connexins.

During controlled experiments, we investigated the influence of the HMP boundary conditions on liver flows.

To tackle this problem, we developed a new software verification technique called oblivious hashing, which calculates the hash values based on the actual execution of the program.

The list below provides examples of verbs that express research actions:

For the object of the document,

• use the document itself as the subject of the sentence: this paper, this letter, etc.;
• use a verb expressing a communication action: presents, summarizes, etc.;
• set the verb in the present tense.

The three examples below are suitable objects of the document for the three tasks shown above, respectively.

This paper clarifies the role of CxHc on calcium oscillations in neonatal cardiac myocytes and calcium transients induced by ATP in HL-cells originated from cardiac atrium and in HeLa cells expressing connexin 43 or 26.

 

This paper presents the flow effects induced by increasing the hepatic-artery pressure and by obstructing the vena cava inferior.

 

This paper discusses the theory behind oblivious hashing and shows how this approach can be applied for local software tamper resistance and remote code authentication.

The list below provides examples of verbs that express communication actions:

A paragraph of results and discussion

This paragraph of results and discussion (above) can easily be rewritten (below) to convey the message first, not last.

When reporting and discussing your results, do not force your readers to go through everything you went through in chronological order. Instead, state the message of each paragraph upfront: Convey in the first sentence what you want readers to remember from the paragraph as a whole. Focus on what happened, not on the fact that you observed it. Then develop your message in the remainder of the paragraph, including only that information you think you need to convince your audience.