An effective introduction establishes the topic’s significance, provides enough context for the reader to follow the argument, and presents the thesis statement. The examples below demonstrate how these elements work together in practice, illustrating the principles described in iResearchNet’s guide to writing an introduction. Each example includes commentary analyzing its structural choices and explaining what makes it effective. All examples are original compositions created for instructional purposes.
Example 1: Problem Opening (Social Sciences)
The United States incarcerates more people per capita than any other nation — approximately 1.9 million individuals in state and federal prisons and local jails as of 2023, a rate of roughly 540 per 100,000 residents. This incarceration rate is five to ten times higher than those of other Western democracies, including Canada, the United Kingdom, Germany, and France, despite comparable or higher crime rates in several of those countries. The human, social, and fiscal costs of mass incarceration — family disruption, community destabilization, reduced lifetime earnings for formerly incarcerated individuals, and annual correctional expenditures exceeding $80 billion — have prompted a bipartisan reexamination of sentencing policy at both the federal and state levels. Central to this reexamination is the question of whether mandatory minimum sentences, which remove judicial discretion for certain categories of offenses, have achieved their intended purpose of reducing crime. This paper argues that mandatory minimum sentences for nonviolent drug offenses have not reduced drug trafficking or drug use and have disproportionately increased incarceration among Black and Hispanic men, and that restoring judicial sentencing discretion would produce better outcomes for public safety, racial equity, and fiscal responsibility.
Commentary: This introduction opens with a striking statistic (the U.S. incarceration rate) that immediately establishes the topic’s scale and significance. The second sentence provides international comparison, which frames the U.S. rate as exceptional rather than inevitable. The third sentence identifies the costs, broadening the reader’s understanding of why the topic matters. The fourth sentence narrows to the specific policy question (mandatory minimums) that the paper will address. The final sentence presents the thesis — a three-part claim about ineffectiveness, racial disparity, and the superiority of the alternative. The funnel moves smoothly from broad context (incarceration) to specific argument (mandatory minimums should be eliminated).
Example 2: Scholarly Debate Opening (Humanities)
Critics have long debated whether Hamlet’s famous delay — his failure to act swiftly on the Ghost’s command to avenge his father’s murder — reflects a psychological condition, a moral dilemma, or a dramatic convention inherited from the revenge tragedy tradition. Romantic-era critics, most influentially Coleridge and Goethe, read the delay as evidence of Hamlet’s excessive intellectualism: a mind too refined for the crude demands of action. Psychoanalytic critics, following Freud and Ernest Jones, located the delay in Hamlet’s unconscious identification with Claudius, whose murder of the father and marriage to the mother enacts the Oedipus complex that Hamlet cannot consciously acknowledge. More recent historicist readings have situated the play within early modern debates about the ethics of revenge, the reliability of supernatural testimony, and the political dangers of tyrannicide. Each of these traditions illuminates aspects of the play, but each also forecloses questions that the text itself insistently raises. This paper argues that Hamlet’s delay is best understood as an epistemological crisis rather than a psychological or moral one: the play dramatizes the impossibility of achieving the certainty of knowledge that revenge, understood as a form of justice, demands.
Commentary: This introduction opens by naming the scholarly debate directly — the reader immediately understands that the paper will enter a long-standing critical conversation. The middle sentences survey three major interpretive traditions (Romantic, psychoanalytic, historicist), demonstrating the writer’s command of the secondary literature and positioning the argument in relation to existing scholarship. The penultimate sentence acknowledges the value of previous readings while identifying their limitation (each “forecloses questions that the text itself insistently raises”). The thesis — proposing an epistemological reading — appears at the end as a new contribution to this conversation, not as an isolated claim but as a response to the inadequacies of previous approaches.
Example 3: Contextual Opening (Health Sciences)
In 2023, the American Nurses Association reported that 62 percent of registered nurses in the United States described their workload as unsustainable, and more than one in five planned to leave direct patient care within the next two years. These figures represent a significant escalation from pre-pandemic levels, when approximately 15 percent of nurses reported intent to leave. The COVID-19 pandemic accelerated trends that had been building for decades: chronic understaffing, mandatory overtime, rising patient acuity, and insufficient institutional support for the emotional demands of clinical work. While attention has focused on pandemic-specific stressors — exposure risk, PPE shortages, moral distress from triage decisions — the structural factors that drive nurse burnout predate COVID-19 and will persist long after the pandemic’s acute phase has passed. This paper examines the relationship between nurse-to-patient staffing ratios and nurse burnout in U.S. acute care hospitals, arguing that state-mandated minimum staffing ratios — modeled on California’s 2004 legislation — represent the most effective policy intervention for reducing burnout, improving patient outcomes, and retaining experienced nurses in the profession.
Commentary: This introduction opens with current data (ANA workforce survey) that establishes the problem’s urgency. The second sentence provides pre-pandemic comparison, which shows that the current crisis represents an acceleration rather than a new phenomenon. The third and fourth sentences provide historical and structural context, distinguishing between pandemic-specific and structural causes — a distinction that is central to the paper’s argument. The thesis, positioned at the end, makes a specific policy claim (mandated staffing ratios) supported by a specific evidence base (California’s 2004 legislation) and identifies three outcomes the paper will evaluate (burnout reduction, patient outcomes, nurse retention).
Example 4: Question Opening (Education)
What happens to a school’s curriculum when every subject must compete for instructional time against the subjects that appear on a state-mandated standardized test? Since the passage of the No Child Left Behind Act in 2002 and its successor, the Every Student Succeeds Act in 2015, U.S. public schools have operated under accountability frameworks that tie funding, school ratings, and personnel decisions to student performance on standardized assessments in English language arts and mathematics. The intended effect — ensuring that all students receive rigorous instruction in foundational skills — is a legitimate policy goal. The unintended effects, however, have been substantial and well documented: reduced instructional time for science, social studies, art, music, and physical education; narrowed curricula that emphasize tested skills at the expense of higher-order thinking; and widened achievement gaps between schools serving affluent and low-income communities, as schools in low-income areas face the greatest pressure to focus exclusively on tested content. This paper examines the curricular effects of high-stakes testing in U.S. elementary schools, arguing that the accountability benefits of standardized testing do not justify the educational costs imposed by the current testing regime and that performance-based assessment systems offer a more educationally sound alternative.
Commentary: This introduction opens with a question that frames the paper’s central concern in concrete, vivid terms. The question is not rhetorical decoration; it is the question the paper will answer. The second sentence provides the policy context (NCLB, ESSA) that the question arises from. The third and fourth sentences present the intended and unintended effects, setting up the paper’s central tension: the gap between the policy’s goals and its consequences. The thesis makes a comparative claim (costs outweigh benefits) and proposes an alternative (performance-based assessment), giving the paper both a critical and a constructive dimension.
Example 5: Data-Driven Opening (Environmental Science)
Between 2000 and 2023, satellite-derived normalized difference vegetation index (NDVI) data reveals that shrub and tree cover expanded northward into Arctic tundra regions at an average rate of 1.2 kilometers per decade — approximately 40 percent faster than the rate projected by the ensemble mean of CMIP6 Earth system models for the same period. This discrepancy between observed and modeled Arctic greening has significant implications for climate projections, because vegetation expansion in the Arctic triggers feedback mechanisms — reduced surface albedo, increased evapotranspiration, and accelerated permafrost thaw releasing stored carbon — that amplify regional and global warming. Despite growing observational evidence of accelerated greening, the feedback pathways linking vegetation change to permafrost dynamics remain poorly represented in the models used to inform international climate policy. This paper analyzes the divergence between observed Arctic greening rates and CMIP6 model projections using satellite NDVI data from the MODIS and Landsat archives, argues that the models systematically underestimate the rate of vegetation-driven feedback in high-latitude regions, and identifies the specific model parameters — soil thermal conductivity, root-zone depth, and vegetation-albedo coupling — that require recalibration to bring projections into alignment with observational data.
Commentary: This introduction opens with specific quantitative data — a measured rate compared to a modeled rate — that immediately establishes the paper’s empirical foundation and signals that the argument will be grounded in data rather than speculation. The second sentence explains why the discrepancy matters (feedback mechanisms that amplify warming), establishing stakes that extend well beyond the technical question of model accuracy. The third sentence identifies the research gap: the feedback pathways are “poorly represented” in the models used for policy — a statement that connects the technical finding to its real-world significance. The thesis is the most specific of any example on this page: it names the data sources (MODIS, Landsat), the model ensemble (CMIP6), the claim (systematic underestimation), and the specific parameters that need recalibration. This level of specificity is characteristic of scientific introductions, where precision is valued over rhetorical elegance.
Note the introduction’s structure: it begins with an empirical observation (what the data shows), moves to significance (why it matters), identifies the gap (what the models miss), and presents the thesis (what the paper will demonstrate). This is the standard scientific introduction structure, which compresses the funnel into a tighter, more data-focused progression than the social science or humanities introductions above.
Example 6: Historical Narrative Opening (History)
On the morning of March 25, 1911, a fire broke out on the eighth floor of the Asch Building in lower Manhattan, where the Triangle Shirtwaist Factory employed more than 500 workers — most of them young immigrant women from Italy, Russia, and Eastern Europe. Within eighteen minutes, 146 workers were dead, killed by flames, smoke, or the desperate leap from windows nine stories above the sidewalk. The locked exit doors, the collapsed fire escape, and the absence of sprinklers or fire drills were not failures of technology; they were consequences of a regulatory framework that treated factory safety as a matter of employer discretion rather than public obligation. The Triangle fire did not create the Progressive-era labor reform movement — that movement was already underway — but it provided the political catalyst that transformed diffuse public sympathy for workers into concrete legislative action. This paper examines how the Triangle fire and the public outcry it provoked enabled Frances Perkins, Robert Wagner, and Al Smith to overcome decades of industry opposition and pass the most significant package of workplace safety legislation in New York State history, establishing regulatory precedents that would shape federal labor law for the remainder of the twentieth century.
Commentary: This introduction opens with a specific historical event described in vivid, concrete detail — the fire’s location, its victims’ demographics, and the eighteen-minute timeline. The narrative opening draws the reader into the human reality of the event before shifting to analysis in the third sentence, which reframes the fire’s causes as regulatory failures rather than accidents. The fourth sentence positions the fire within the broader historical context of the Progressive-era reform movement, qualifying the event’s significance (it was a catalyst, not an origin). The thesis identifies the specific actors (Perkins, Wagner, Smith), the specific achievement (workplace safety legislation), and the specific historical significance (establishing precedents for federal law). This introduction demonstrates how historical writing uses narrative to establish context before advancing an analytical claim — the story serves the argument, not the other way around.
Note the precision of the thesis: it does not merely argue that the Triangle fire was “important” or “changed history.” It specifies what changed (legislation), who changed it (named individuals), what they overcame (industry opposition), and why it mattered beyond the immediate context (federal precedents). This specificity is what distinguishes a strong historical thesis from a vague one.
Example 7: Concession Opening (Psychology)
The claim that violent video games cause real-world aggression has been one of the most persistent and politically charged debates in psychology for more than two decades. Early experimental studies — most prominently Anderson and Bushman’s (2001) meta-analysis — found significant positive associations between violent game exposure and aggressive thoughts, feelings, and behavior, leading the American Psychological Association to issue a resolution in 2005 linking violent media to aggression. More recent research, however, has complicated this consensus substantially. Longitudinal studies with larger and more representative samples have found smaller and often non-significant effects after controlling for confounding variables such as family environment, pre-existing conduct problems, and socioeconomic status. The 2020 APA task force acknowledged this evolving evidence base by softening its previous position, concluding that while violent video games may be a risk factor for aggression, the evidence is “insufficient” to establish a causal link to criminal violence. This paper argues that the early experimental evidence for a causal relationship between violent video games and real-world aggression was methodologically compromised by small sample sizes, demand characteristics, and the use of laboratory aggression measures with limited ecological validity, and that the longitudinal evidence — which is more methodologically rigorous — does not support a meaningful causal effect.
Commentary: This introduction uses a concession opening — it begins by presenting the opposing view (violent games cause aggression) and the evidence that initially supported it before introducing the complications that undermine it. This structure is particularly effective for papers that argue against a widely held position, because it demonstrates that the writer understands and takes seriously the evidence on the other side before presenting a counterargument. The reader sees that the writer is engaging with the strongest version of the opposing case rather than setting up a straw man.
The narrative arc of this introduction — early consensus, complicating evidence, institutional acknowledgment of uncertainty, and then the thesis — mirrors the intellectual history of the debate itself, which gives the introduction a sense of movement and development rather than a static statement of position. The thesis is long (two sentences would be acceptable here) but precise: it identifies the specific methodological problems with the early evidence and the specific reason the longitudinal evidence is more trustworthy.
Structural Patterns Across Examples
Several patterns recur across these introductions that students can apply to their own papers.
Every introduction moves from general to specific. Each opens with a broad statement of the topic’s importance and narrows progressively to the paper’s specific claim. The narrowing is smooth and logical — each sentence follows naturally from the one before it, and the thesis arrives as the culmination of the setup rather than as a surprise.
Every introduction establishes stakes. The reader understands, before encountering the thesis, why the topic matters — because of its human costs, its intellectual significance, its policy implications, or its relevance to an ongoing scholarly conversation. A thesis presented without stakes feels arbitrary; a thesis presented after stakes have been established feels necessary.
Every thesis appears at the end. This placement gives the thesis maximum impact because the reader has been prepared to receive it. The context provides the meaning; the thesis provides the direction.
Every introduction identifies a gap, tension, or problem. The contextual opening identifies a gap between incarceration rates and public safety outcomes. The scholarly debate opening identifies competing interpretations that the paper will adjudicate. The health sciences opening identifies a structural problem that existing research has not adequately addressed. The data-driven opening identifies a discrepancy between observed data and model predictions. The historical opening identifies a catalytic event whose legislative consequences have not been fully analyzed. The concession opening identifies a gap between early findings and more rigorous later evidence. In each case, the paper exists because something needs explaining, resolving, or correcting — and the introduction makes that need visible before presenting the thesis as the response.
Opening strategies match disciplinary expectations. The social science introduction leads with a statistic. The humanities introduction leads with a scholarly debate. The health sciences introduction leads with workforce data. The environmental science introduction leads with satellite measurements. The history introduction leads with a narrative. The psychology introduction leads with a concession. Each opening signals the disciplinary context and the type of evidence the paper will use. Students should examine published introductions in their discipline’s leading journals to identify which strategies are conventional and which are innovative.
Commentary length reflects analytical depth. The commentary following each example is not filler — it identifies the structural choices the writer made, explains why those choices are effective, and connects the specific example to general principles that the student can apply to their own introductions. Students reading these examples should focus on the commentary as much as on the introductions themselves, because the commentary makes explicit the reasoning that experienced academic writers perform intuitively.
Every introduction is proportional to the paper. The length of these sample introductions (150 to 300 words each) is appropriate for papers of ten to twenty pages. Shorter papers need shorter introductions; longer papers may need longer ones. The introduction should provide enough context for the thesis to make sense — no more, no less.
For the complete guide to writing introductions, including additional opening strategies and advice on writing the introduction last, see iResearchNet’s guide to writing an introduction.
Related Pages
- How to Write an Introduction for a Research Paper — Principles of introduction construction
- How to Write a Research Paper — Complete step-by-step guide
- Research Paper Thesis Statement Examples — Sample thesis statements across disciplines
- Research Paper Outline Examples — Sample outlines at different levels
- How to Write a Body of a Research Paper — Building the argument paragraph by paragraph