The Discussion section is where interpretation gets done, limitations are pointed out, and speculation occurs. This is usually the section everyone has been waiting to write! However, before you get too far ahead, there is a manner for writing Discussions which is pretty specific. Imagine the Discussion as a dialogue or dance between your research and other published research. Whether duet or duel, the Discussion proceeds as follows.
- Opening Paragraph — restate the research question and “answer” it based on the major findings of the study
- Body Paragraphs — dialogue with other research by joining your outcomes with the published research in one of four potential relationships:
- Claim — your results show something for the first time (in other words, no other evidence for this result has been published)
- Corroborate – your results clearly support the results of other research thereby increasing the credibility of a particular interpretation/perspective
- Clarify – your results add more information to field of study by refining what is already known about a particular interpretation/perspective (usually impacts scope)
- Contradict – your results clearly conflict with the results of other research thereby decreasing the credibility of a particular interpretation/perspective
- Penultimate Paragraph — brief discussion of limitations
- Final Paragraph — synthesis summary statement + what should come next (research and/or application?)
Opening Paragraph
Think of your readers for a moment: they’ve just worked their way through an opening argument (the Introduction), a design with many moving parts (Method), and a blizzard of data complete with statistics (Results). By the time they come to the first paragraph of the Discussion, readers need a minute to gather their thoughts. Smart writers capitalize on this need by drafting an opening paragraph that fulfills this simple but critical function. Do so by reminding the reader where they’ve been and what it means.
Begin the Discussion section by restating the Research Question and “answering” it with the major findings of your work. The goal here is to provide an easily understood synopsis of what the study reveals.
Example 1 || Control as an Engagement Feature for Young Children’s Attention to and Learning of Computer Content
The purpose of this study was to examine the effects of adult control on young children’s attention to, and memory of, content presented in a computer story. As expected, children were less interested in the story and became less attentive across repetitions when an adult controlled the situation and children had little personal control of the learning situation. These drops in attention were steepest when the adult had total control of the mouse, particularly in the last session. By contrast, when children controlled the session, there was never a significant drop in attention across sessions, a finding that was unique to their group. The results suggest that user control plays an important role as an engagement feature that can facilitate children’s attention to and interest in computer activities.
Example 2 ||
Based on the above results, the answer to the fundamental question, “Are pre-kindergarten children ready for multi-touch technology?” is definitely affirmative, provided certain issues are dealt with. Regarding the question “What multi-touch gestures are children between two and three years of age able to use?”, we found that the general belief that pre-school children are only capable of performing tap and drag interactions is really no more than a myth. Our study found similar levels of success for interactions such as one-finger rotation and two-finger scale up and down, as for tap and drag, already mainstream in existing applications. Consequently, interaction designers have an opportunity to broaden the scope of their interfaces when creating future applications. Current applications for pre-kindergarten children might be missing the opportunity to provide richer gestures within children׳s abilities, and could be using a gesture that is notoriously difficult for them (e.g., double tap or two-finger rotation). Therefore, these results show there is no justification for the current situation of most commercial applications for pre-kindergarteners which only support two gestures: tap and drag (present in 99% and 56% of the analyzed applications, respectively).
Analysis: The early sentences (in blue) provide a simple restatement of the research question. The rest of the paragraph answers the question with sentences that convey the major ideas according to outcomes. They also supply brief statements of what the research contributes overall.
Stylistics Note: The orange colored phrases show that the writer can “add” some logical markers back into the text and that doing so emphasizes the major pieces of information the reader should pay attention to. The underlined and bolded verbs highlight an interesting feature of science prose: tenses can vary in a paragraph. The variation is generally dictated by the kind of information being conveyed. When the sentence is about what happened in the research, use the past tense. When the sentence is about what an outcomes means, then use the present tense.
Not every paper restates the RQ (though this is a good idea if the method and results were complicated and long; if you needed subheadings, consider restating the RQ). The examples below jump right in with the the major findings of the study. Still, this provides the reader much needed text-based expression of data points in a coherent form that reinforces how the data relate to each other and the study’s overall goals.
Example 3 ||
The main findings of this study are as follows: (1) postnatal HS intake aggravates prenatal HF-induced programmed hypertension in 12-week-old male offspring, (2) maternal HF intake- and postnatal HS intake-induced programmed hypertension may not be related to the ADMA–NO pathway, (3) HF and HS differentially regulate RAS components, (4) postnatal HS intake increases renal levels of NHE3, NCC, and NKCC2 but prenatal HF exposure does not, and (5) postnatal HS increases Sgk1 expression, which is blunted by maternal HF intake.[5]
Example 4 ||
Overall, attitudes and perceptions of both urban and rural primary care patients in this sample show that they are generally receptive to the possibility of receiving medical and psychiatric services via telehealth. Comfort and confidence in consulting with a provider for a range of medical services and comfort using telepsychiatry in different settings ranged from “a little bit” to “moderately.” Furthermore, there were no statistically significant differences between rural and urban participants on these items. With regard to concerns with telepsychiatry as a medium of care, only a small percentage of the sample believed that the information technology would be too sophisticated, that a telehealth application would not help their problems and/or expressed concerns regarding what others would think.
Body Paragraphs
Functionally, the purpose of a Discussion section is to explicitly demonstrate how the new information generated by a study fits into what is already known. Specifically, the Discussion section does this by placing the new results vis-a-vis published results and speculating on what this means. However, there are some unstated rules in place governing how this speculation takes place! Our impulse is to make logical leaps beyond what is reasonably supported for in the data. The solution that constrains the writer’s enthusiasm is to set up the Discussion itself as a “dialogue” between your work and everyone else’s. In other words, for every result you want to discuss, you will either claim your outcomes are the first of their kind or find some evidence in the current literature which your data corroborates, clarifies, or contradicts. The general pattern goes “My result — Other Result — Relationship — Discussion”, though there is quite a lot of variation on this theme!
- Claim — results show something for the first time (in other words, no other evidence for this result has been published)
- Words/Phrases: We are the first to show/ Our results are the first to reveal / We have shown for the first time / To our knowledge, we are the first to demonstrate / Our approach is the first to reveal / Our study is the first to employ X / Our results are the first to clearly demonstrate (stronger version) / For the first time, we have conclusively elucidated (stronger version)
- Corroborate – results clearly support the results of other research thereby increasing the credibility of a particular interpretation/perspective
- Words/Phases: similarly / similar to / support / corroborate / support and extend to / also
- Clarify – results add more information to field of study by refining what is already known about a particular interpretation/perspective (usually impacts scope) but does not disprove/conflict
- Words/Phrases: logical connectors use heavily to create a complete statement, e.g. “A but not B” or “A, but only in the context of B” or “A and B, however C, though also D”
- Contradict – results clearly conflict with the results of other research which may decrease the credibility of a particular interpretation/perspective or may suggest areas of further research to resolve situation
- Words/Phrases: Unlike X, we found / In contrast to X, we show / Our results contradict those found by X / Our results cast doubt on the interpretation of X results / Our results suggest the explanation for Y is more likely to be Z
Claim
Example Unilateral subdural motor cortex stimulation improves essential tremor but not Parkinson’s disease
This is the first study reporting double-blinded outcomes from unilateral subdural motor cortex stimulation in patients with essential tremor and Parkinson’s disease. After 3 months of optimal stimulation, unilateral subdural motor cortex stimulation significantly improved contralateral hand tremor in six patients with essential tremor, but was not effective in improving motor signs in five patients with advanced Parkinson’s disease.
Corroborate
Example || Control as an Engagement Feature for Young Children’s Attention to and Learning of Computer Content
For recognition of visual story-related responses, the only treatment difference was between all treatment conditions and the control group who received no exposure to the content. Consistent with previous literature (see Calvert, 1999), boys tended to remember more visually presented content.
Example || Understanding performance in touch selections: Tap, drag and radial pointing drag with finger, stylus and mouse
Sasangohar et al. (2009) compared tapping performance between direct finger touch input and a mouse. They report that movement times ranged from 403 ms to 1051 ms using touch and from 607 ms to 1323 ms using the mouse, giving a 33% performance benefit for the finger with low index of difficulty tasks and a 26% benefit in high difficulty tasks. These results support our findings for the finger and mouse comparison in tapping tasks, where the finger’s performance benefit over the mouse ranged from 39% (low difficulty) to 32% (high difficulty). Sasangohar et al. (2009) also reported that the error rate with the finger (mean 9.8%) was much higher than the mouse (2.1%), which reflects our results (finger mean 6.8%; mouse mean 3.1%)
Clarify
Example || Understanding performance in touch selections: Tap, drag and radial pointing drag with finger, stylus and mouse
MacKenzie et al.’s (1991) analysis of tapping and dragging tasks with the mouse, indirect stylus and trackball showed that the mouse and stylus performed similarly in tapping tasks, with a slight performance advantage for the stylus over the mouse. Our results show the same slight advantage. One difference between MacKenzie et al.’s (1991) results and our own is that their dragging tasks were completed more slowly than tapping tasks (particularly so with the mouse), while ours were not. This difference across studies warrants further investigation, but we suspect it stems from a major difference in experimental methodology. In MacKenzie et al.’s (1991) study, ten bidirectional trials at the same amplitude and width were completed together, with the completion of one trial automatically initiating the next. Consequently, participants could adapt across the ten repeated trials to the precise motor actions required for the acquisitions. In our experiment, however, blocks of trials at the same A and W value were shorter (four to the left and four to the right) and involved a stationary timeout between each trial. Our methodology may have provided less opportunity for participants’ to calibrate their finger, forearm and wrist movement to the same paired targets [same citation as above]
Contradict
Example ||
Previous studies showed that consumption of low-salt diet inhibits HF-induced hypertension and kidney damage in adult [15] and [16]. Our previous study showed that mechanisms underlying the development of programmed hypertension in offspring might be different from those in adult rats [6]. For example, uric acid is elevated in fructose-fed adult rats [17] but not in maternal fructose-fed offspring [5]. Oxidative stress and NO deficiency are the key mediators of fructose-induced hypertension [18]. We and others have shown that an early shift in ADMA–NO balance toward increased oxidative stress induces programmed hypertension in later life [19] and [20]. However, ADMA-related parameters were not different among the 4 groups in the present study. Therefore, ADMA-induced oxidative stress might not be the major factor contributing to programmed hypertension in this model.
Example: || Control as an Engagement Feature for Young Children’s Attention to and Learning of Computer Content
For comprehension of the targeted written words, only reading skills predicted children’s recognition of specific written words that had been presented in the story. Our findings did not support those found in the television literature where adult mediation improves children’s learning of content, particularly girls’ learning of verbally presented content (e.g., Friedrich & Stein, 1975). Instead, we found no impact of adult mediation on children’s learning of verbal content, and attention was actually.
Mixing it Up
Example: ||paste here
In patients with Parkinson’s disease, our results confirm the overall negative outcomes found in two previous open studies (Cilia et al., 2007; Gutiérrez et al., 2009) and are in contrast to other open data showing motor improvement after unilateral epidural motor cortex stimulation (Canavero et al., 2002, 2003; Pagni et al., 2005; Benvenuti et al., 2006; Cioni, 2007; Arle et al., 2008). There was a progressive worsening of motor signs and activities of daily living regardless of stimulation on or off. In particular, the ON-medication condition was markedly worse at 1 year compared with before surgery. These observations, together with the progressive worsening of the cognitive performance in two patients, could be evidence for a negative impact of motor cortex stimulation in patients with Parkinson’s disease.
What happens when there’s no clear relationship to published material?
Sometimes, a study participates in a broader “conversation” with published results rather than a dialogue. This is especially true for research featuring novel methodology; something might have provoked certain elements of the design, but the whole point of the research was to employ something for the first time. In these cases, the Discussion section reads more like a long “Clarify” section, with published research being referenced when the context requires, but the writing really emphasizing researcher’s interpretation and explanation of results on their own.
Example || paste here
We processed the EMG signals according to our hypothesis that they can predict the kinematics of slow, unloaded movements. Firstly, we selected the bandwidth between 7.5 and 15 Hz because during low level muscle contractions, EMG power is more concentrated therein [23]. Secondly, EMG waveforms were truncated according to where the flexion data reached 60% of the total ROM, i.e. initial accelerative phase, as adapted from previous studies [8], [15], [24], [25] and [26]. Our fixed truncation window differs from a previous study that applied a variable window to the agonist EMG during a single-joint ballistic movement [27]. Truncation enveloped most of the relevant agonist activity, which is expected to occur near the early phase of the movement when the forearm is accelerated. By comparing the truncated EMG to the full kinematic profile, we were able to observe the impact of alterations of the initial agonist EMG on the entire movement.[2]
Stylistics Note: You may have noticed that authors rarely make strong, specific claims. Although there are places where researchers are unequivocal about reporting results (especially when making Claims), mostly authors use hedge words, such as “may” and “seem” or create careful assertions with phrases such as “could be evidence for” or “might not be the major factor.” This is not wishy-washy science. In fact, this is how the communication of discovery is managed – very, very carefully. Too often over the course of science history, whole belief systems have been overturned because new data or tools have proved ideas proved inaccurate. Rather than declaring a thing is true or proved, practicing scientists offer “best guesses” – assertions about what might be true based on what we know right now.
Limitations
Limitations are those factors or influences that impacted outcomes but were beyond the researcher’s control. In most research, listing all actual limitations would entail a ridiculously long list (money, people, time, resources…). In a research report, the discussion of limitations focuses on specific factors that could have forced outcomes in a direction that was unanticipated or unavoidable. Given that, not all research reports include explicit discussions of limitations, especially when the study subjects don’t have self-initiated behavior (such as animals and humans do!).
When discussing limitations, keep it short, objective, and focused sternly on those factors which could impact interpretation of the results, particularly generalizability. Readers understand that it’s impossible for a study to control all potential influences; nevertheless, you must address limitations that impact how outcomes can be understood and for whom they are credible. Doing so increases the reader’s confidence in the researcher’s integrity.
Minimally, you should acknowledge relevant limitations, written in their own paragraph. Maximally, as demonstrated in the examples below, use limitations as a springboard for suggesting future research. Keep in mind that not every limitation is addressable by more research. Limitations in scope or population and method often make good (and obvious) candidates for future research.
4.7. Limitations
Our study was limited by a small sample size, relatively short training duration, heterogeneity in the levels of functioning of participants, and lack of follow up sessions to evaluate carryover of training. Moreover, in terms of behavioral coding of training sessions, the coders were not blinded to the grouping of the child. In addition, our current evaluation was restricted to the assessment of visual joint attention. Although highly relevant especially in the rhythm group, we did not assess auditory joint attention in this study. In the current paper, we restricted our discussion to the duration of social attention episodes; we are currently in the process of analyzing frequency data for social attention. The present study was a pilot study meant to provide proof of concept and evaluate the feasibility of rhythm and robotic activities in promoting social attention skills in children with ASD. Therefore, in the current study, we did not tightly control and manipulate the effects of individual musical (pitch, melody, rhythm, etc.) or robotic (animate, inanimate, mobile, humanoid) elements on social attention skills.
Analysis: The list of limitations in the first two sentences are generally expected when studying a disordered human population, but must be acknowledged, especially in light of the intent of the research to serve as a proof of concept paper. Note that the writers also provide a counterpoint to the list by explicitly reminding the reader of this intent.
Example || High salt exacerbates programmed hypertension in maternal fructose-fed male offspring
We did not include other major organs in BP regulation, such as the vasculature and brain, in this study. As such, additional studies are needed to elucidate the engagement of other mechanisms of BP control in HF and HS-induced programmed hypertension, such as sympathetic nervous system [28]. A second limitation is that we did not examine possible therapeutic approach in this study. Since that NCC was increased in both HS and HF + HS groups and that activation of renal β-adrenergic-WNK4-NCC pathway plays a role in salt-sensitive hypertension [29], this pathway may be a therapeutic target for the programmed hypertension.
Analysis: This statement of limitations does not carry its own label, but is simply a paragraph that follows the discussion and precedes the final synthesis statement. Note that the writers use the study’s limitations to suggest future research, framing their limitations as opportunities.
Synthesis and Future Work
The Discussion section concludes with a synthesis of the research. Note — this is NOT a summary! The reader does not need a summary of the paper they just read. Instead, provide a synthesis of what the research accomplished vis-a-vis the field of study: what do we know now that we didn’t know before? how does the research contribute overall?
Logically, following the synthesis statement of your contribution comes the statement of what should happen next. Suggestions for future research should follow closely the outcomes and questions wrought by your work. Be explicit about what should be studied; rather than “more research is required”, specify what kind/type/area of research should come next.
Just as with future research, if your study merits application, explain in what specific areas or to which tasks your work can be applied.
Example || (research)
These data suggest that primary care patients, regardless of rural or urban living status, are at least moderately receptive to telehealth as a medium of care. Importantly, rural patients, who are more likely to benefit from telehealth interventions as a means of improving access to care, are no more reluctant to use such services than their urban counterparts. These data are all the more encouraging in light of extant data, which suggests that attitudes toward mental health use are positively associated with actual service use (e.g., Lin and Parikh, 1999; Mackenzie et al., 2004). Future research efforts are needed to develop effective strategies for improving the acceptability and ensuring the appropriate use of telehealth care for those patients who may be positioned to benefit from it.
Analysis: The blue sentence is the synthesis statement — the big idea that this piece of research adds to our knowledge about this topic. The orange sentence supplies the specific recommendation for future research.
Example || (application)
Our model of the current study is based on the widespread consumption of food and drinks containing high sugar and salt by pregnant mothers and their children. Our findings indicate that postnatal HS intake exacerbates maternal HF intake-induced programmed hypertension. HF and HS diets differentially regulate RAS and sodium transporters to promote hypertension. These findings can form a strong scientific basis for developing therapeutic strategies to improve fetal development and to prevent programmed hypertension in later life.
Analysis: The blue sentence is the synthesis statement. The orange sentence suggests a particular application of this work.
What about Conclusions?
Some research articles include both a Discussion section and a Conclusion. Most frequently, a Conclusion is supplied when the writer has presented Results and Discussion together. The Results-Discussion combination works particularly well when a study had distinct trials or populations in the method. For each distinguishing feature, the writers present Results (just as done in a standard Results section) followed immediately by the Discussion of those results. In this case, the Discussion portions ONLY involve the immediately preceding Results. Thus, the reader still needs a statement that communicates the overall impact of the study. This is what the Conclusion provides.
When using a combined Results-Discussion, the functional labels are both included in the main heading. To keep information clear, each results-discussion pair should also have its own subheading.
Example || paste here
3.2. Coagulation behavior of the dual coagulants as a function of alum dosage
Different types of coagulants will impact the characteristics and coagulation of effluent water. To determine the optimal coagulant dosage for a given test water, experiments were conducted with a fixed AHF dosage and two coagulants (PACl and Al2(SO4)3). The coagulant doses ranged from 2 to 12 mg Al/L, and the AHF dosage was maintained at 20.5 mg Al/L. The DOC, UV254 and turbidity removal of PACl, PACl–AHF, Al2(SO4)3 and Al2(SO4)3–AHF were comparatively investigated as a function of the alum dosage, and the results are shown in Fig. 3. For PACl, the removal efficiency of DOC and UV254increased as the alum dosage increased and reached an optimal dose at 9 mg Al/L. For Al2(SO4)3, the optimal dosage was 11 mg Al/L. Cheng [5] considered charge neutralization and adsorption as the possible coagulation mechanisms that removed humic acid. Gregory and Kam [21] reported that the removal of humic substances was significantly dependent on the neutralization of negative charges during the coagulation process and that adsorption and bridging mechanisms did not play significant roles. In our study, the results showed that the DOC and UV254 removal efficiencies of PACl and Al2(SO4)3 reached their optimal values when the zeta potential values of the solutions were close to zero (Fig. 3(b)). Therefore, it seems that charge neutralization is the predominant mechanism for the removal of organic matter by PACl and Al2(SO4)3.Moreover, the use of PACl resulted in a steeper increase in the zeta potential than Al2(SO4)3. Therefore, PACl could potentially achieve a larger HA removal efficiency.
4 Conclusion
In this study, the coagulation aid effect of AHF was investigated. AHF could be used as a new type of coagulant aid due to its notable effects. AHF is a type of waste discharged from drinking water treatment plants and can be recycled to provide significant application values to strengthen traditional water treatment methods and improve effluent quality. Due to the lack of apparent change in zeta potential, physical adsorption was likely the primary mechanism by which AHF removed organic matter. When AHF was applied with PACl and Al2(SO4)3, the organic material and residual turbidity removal rates were significantly improved. The changes in the zeta potential values indicated that charge neutralization was not the only dominant mechanism for these dual coagulants; entrapment and adsorption also played significant roles. The extra adsorption bridge ability for PACl resulted in flocs having more compact structures than flocs formed by Al2(SO4)3 via simple charge neutralization. The addition of AHF played a significant role in improving the floc structure. Flocs were further developed with large sizes and fractal dimensions, especially at the steady state stage. When compared with traditional coagulants, while the dual coagulants triggered slightly larger releases of DOC after breakage, the regenerated flocs with larger sizes and more compact structures could be used as adsorbents to further remove organic matter.
Analysis: In the combined Results-Discussion paragraph, the green sentences report Results; the purple report the body of the discussion; the bolded purple names the relationship, in this case, both corroboration and clarification. The red sentence implies an area for future research. Note that the Discussion material only refers to the immediately preceding Results. The Conclusion starts with a brief restatement of the research question with the big-idea statement about outcomes (the blue sentences), similar to the opening salvo of a standard Discussion section. The rest of the conclusion synthesizes the major contributions of each of the three Results-Discussion sections. The final sentence suggests how this information can be applied (and also, a logical focus for future research).