Ch13

Scientific Writing and Communication, 2e Angelika H. Hofmann Copyright © 2014 by Oxford University Press

Chapter 13

Discussion


• Answers the question posed in the Introduction

• Also explains:

o How the results support the answer

o How the answer fits in with existing knowledge

o Theoretical implications or practical applications

Function of the Discussion


• Provide the answer to the question • State and interpret key findings

• State the novelty and significance/importance

• Indicate possible next steps

• Provide other relevant results and hypotheses

• Compare and contrast your findings with others

• Can mention possible errors, unexpected findings, or limitations

Content of the Discussion

Summarize and generalize


• Consider readers

• Basic scientists and clinicians need to understand each other

• Provide clinical implications

• Discuss scientific significance

• Take a stand—convey confidence and authority

Audience and Tone in the Discussion


Pyramid structure: Specific to general

- The answer - Your interpretation of the answer - Supporting evidence

- Comparisons/Contrast with previous studies - Unexpected findings and limitations - Hypotheses or models

- Summary and significance

First Paragraph

Middle paragraphs

Last paragraph

Organization of the Discussion


The verb tense depends on the subject of the sentence

Signal Verb Tense

This study shows that Present

Our results indicate that Present

In this study, we provide evidence that

Present

In this study, we have shown that Present perfect

In this study, we have found that Present perfect

In this study, we found that Past

Signal of the Answer


State the answer/interpret key findings

• Answer ≠ ResultsAnswer = Generalization based on the results

Support the answer

• State the relevant results after stating the answer

• Cite a figure or a table if necessary

• Readers will not memorize results or search for them

First Paragraph


Transition Type

“In our experiments” Transition phrase

“The evidence is that” Transition clause

“Evidence that (answer) is that” Transition clause

“We found that”* Transition clause

“(Answer) has been demonstrated in two ways.”

Topic sentence

*Only if “We found that” is not used to signal the answer.

Transitions from the Answer to the Results


Example

Our findings emphasize the need to continue to promote personal protection measures to reduce the risk of Lyme disease infection. We have identified three reasonable personal measures that may be protective against Lyme disease when practiced: tick checks, bathing, and insect repellents. Performing tick checks within 36 hrs after spending time in the yard may reduce one’s risk by as much as 46%. In addition, bathing may reduce one’s risk by up to 57%, and the use of insect repellent may be protective against the disease up to 75%.

AnswerAnswer

Supporting evidenceSupporting evidence

Sample Discussion First Paragraph


Do not begin the Discussion with:

• A second introduction

• A summary of the Results

• Secondary information

How Not to Begin the Discussion


• Organize the topics: most to least important

• Compare and contrast results

• Explain discrepancies, unexpected findings, and

limitations

• Provide generalizations (models) where possible

Middle Paragraphs


• Use topic sentences

• Repeat key terms

• Use Transitions- Stronger transitions in later paragraphs

• Consider word location

Continuity in the Discussion


Mention any results that do not support your answer

Explain discrepancies with other’s work

Example

Apparent discrepancies between our values and those of earlier studies may be due to differences in study design. In our study, oxygen was excluded in all cases. Moreover, aluminum was added. Earlier studies that reported lower reaction rates, differed from this study design in one of two ways: No care was taken to exclude oxygen, or a mixture of different metal alloys was added.

Conflicting Results


Discuss unexpected findings

•State that the finding was unexpected (or surprising)

•Explain unexpected findings as best you can

•Unexpected findings may be important

Example To our surprise we discovered that the bindin fusion

protein was being cleaved during isolation and purification. The proteolysis is remarkably efficient since only small amounts of the unprocessed form remain (Fig. 2, lane 3).

Unexpected Findings


Provide a conclusion

•Restate the answer(s) to the question(s)

•Indicate the importance of the work

•Discuss theoretical and possible practical implications

Last Paragraph


Phrase conclusions concisely and with great care

Signal the end and signal the answer

Examples

• “In summary, we have shown that . . .”

• “In conclusion, this study shows that . . .”

The Conclusion

Answer at the end of the Discussion = Answer at the beginning

Answer at the end of the Discussion = Answer at the beginning


Level of Certainty

Indicate importance by stating

Importance of Work

Ending Example

Application . . . can be used for . . .

Advice X should be used to . . .

Suggestion Our results imply . . .

Proposition We hypothesize that . . .


Example Application

In summary, our work reveals the functional interactions involved in the binding of antibiotics to the peptidyl transferase cavity of the bacterial ribosome. None of the antibiotics examined show any direct interaction with ribosomal proteins. Chloramphenicol targets mainly the A site, where it interferes directly with substrate binding. Clindamycin interferes with the A site and P site substrate binding and physically hinders the path of the growing peptide chain. Macrolides bind at the entrance to the tunnel where they sterically block the progression of the nascent chain. The structural model of the peptidyl transferase center in complex with the examined antibiotics can not only enable a rational approach for antibiotic development and therapy strategies but can also be used to identify new target sites on the eubacterial ribosome.

Sample Conclusion

AnswerAnswer

Key findings

Key findings

SignificanceSignificance


Tense in the Discussion

• Past tense for results

• Present tense for general statements and

conclusions

• Be specific about necessary future studies


Signals in the DiscussionAnswer Key findings Summary Significance

In this study, we have shown . . .

In our experiments . . .

In summary, . . . Our findings can/will serve to . . .

In this study, we found that . . .

. . . can be attributed to . . .

In conclusion, . . . Finally, . . .

. . . can be used . . .

Our study shows that . . .

We found that . . .

To summarize our results, . . .

Y should be used for . . .

Our findings demonstrate that . . .

Our data show that . . . was demonstrated by . . .

We conclude that . . .

Taken together, . . .

Y indicates that X may . . . These findings imply that X may . . .

This paper describes . . .

Overall, . . . . . . we hypothesize that . . .


Signals in the Discussion

Comparisons Conflicting Results

Limitations Unexpected Findings

Proposed Hypothesis

. . . consistent with . . . (ref.)

Similar to . . . (ref.)

. . . has also been observed by . . . (ref.)

X has been demonstrated . . . (ref.)

However, other studies found that . . . (ref.)

. . . is controversial . . . (ref.)

. . . does not agree with (ref.)

. . . has also been reported… (ref.)

. . . was not possible . . .

. . . could not be measured . . .

. . . was limited by . . .

Further observations are needed to . . .

Surprisingly, . . .

To our surprise . . .

. . . was not expected.

Our results lead to the conclusion that . . .

From these data we hypothesize that . . .

We propose the following new principle . . .

ref. = reference


• The Results and Discussion sections are sometimes combined

• Advantageous for certain papers

• The results are discussed as they are presented

An Alternative: Results and Discussion


Common Problems of the Discussion

• The answer/interpretation is not provided in the first paragraph

• The importance/significance of the study is not clear

• Inclusion of irrelevant or peripheral information

• Results are repeated or summarized in the Discussion

Ch13

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