Chapter 18 Scientific Grammar Laboratory Reports and Oral Communication

Year 1 · English · G116-L3

Use precise tense, voice, conditions and comparisons to write a short geology report and deliver a clear evidence-based oral explanation.

A repeatable workflow from a testable question to an evidence-based interpretation. Original Geology Hub teaching diagram.

Learning objectives: Select tense and voice for a clear purpose, organize a laboratory report, express uncertainty accurately, and explain a result orally with evidence.

Grammar should clarify who did what

Scientific writing uses both active and passive voice. “We measured the sample mass” identifies the actor directly. “The sample was weighed” emphasizes the object and procedure. Neither construction is automatically more scientific. Choose the form that makes responsibility, sequence and emphasis clear. Avoid hiding an important decision in passive wording when the reader needs to know who selected or rejected a measurement.

Tense distinguishes general principles from particular actions. A general relation may use present tense: “Density equals mass divided by volume.” A completed method often uses past tense: “The specimen was weighed three times.” A prediction can use conditional wording: “If the sample contains open pores, water uptake may affect the volume estimate.” Keep the condition attached to the claim rather than burying it in another paragraph.

Sentence relationships carry scientific meaning

Relative clauses specify or add information about a noun. Prepositions express relationships such as depth below a surface, distance along a section or position within a formation. Conjunctions link causes, contrasts and conditions. “Because” proposes a cause; “although” introduces a limitation or contrast. Misusing these links can change an interpretation even when the technical nouns are correct.

Comparative and superlative forms require a reference. “The upper sample is coarser” should identify what it is coarser than and how grain size was assessed. Modal verbs express possibility, expectation or requirement. “May indicate” is weaker than “demonstrates.” Qualify uncertainty precisely rather than surrounding every sentence with vague hesitation. Scientific confidence comes from matching language to evidence.

A laboratory report is an argument with an audit trail

The introduction states the question and its relevance. Methods describe what was done well enough for another reader to understand the procedure. Results present observations and calculations, while discussion explains their meaning, limitations and relationship to the question. A conclusion gives the supported answer. References identify sources, and appendices can preserve supporting records that would interrupt the main explanation.

Do not mix a result with an unsupported cause. If two density determinations differ, report the difference before explaining possible reasons. Potential causes might include volume-reading uncertainty, pore effects or sample variation, but a possible cause is not established merely because it sounds plausible. Tables and figures need informative captions, units and a clear connection to the surrounding text.

Tense places an assertion in the right context

“Water occupied the fracture” reports an interpreted past condition, while “water occupies the fracture” asserts a present one. “We measured three specimens” identifies a completed action. Passive wording can emphasize the procedure, as in “Three specimens were measured,” but should not obscure a consequential choice about exclusions. A reader needs to distinguish who collected observations from who later reinterpreted them. Grammatical agency therefore supports accountability as well as sentence clarity.

Relative clauses and prepositions identify relationships

“The bed that contains shells” specifies which bed is meant. “The bed, which contains shells, overlies sandstone” adds information about an already identified bed. Prepositions can change geological meaning: a vein within a formation differs from a vein beneath it, and a distance along bedding differs from thickness across bedding. An accurate technical noun cannot repair an incorrect spatial relationship. Include an unambiguous reference surface when describing depth below ground or elevation above a datum.

Conditions and modals express different commitments

“If the grains are detrital, they predate final deposition” connects an inference to its required condition. “The grains may be detrital” instead states uncertainty about that condition. “Because” proposes a cause, whereas “although” signals a limitation or contrast. Replacing “may indicate” with “demonstrates” materially increases a claim’s strength. The wording should change only when the evidence warrants that increase, not simply to make the prose sound more confident.

Comparisons require a reference and a quantity

“Sample A is coarser” is incomplete unless the comparator and measure are clear. “Sample A has a larger median grain diameter than B” identifies the statistic and relationship. An adverb such as “significantly” may imply a statistical test when only a visual difference was observed. State the actual contrast first, with units and justified precision. Distinguish “increased by 20 percent” from “increased to 20 percent,” because one describes relative change and the other a final level.

Report sections make different kinds of sentences

Methods specify the measurement procedure; results report its outcomes; discussion evaluates meaning and alternatives. Suppose a fictional volume reading changes after wetting. The results sentence records the measured change. A discussion sentence may propose pore-water uptake as one explanation, while acknowledging another possibility such as reading error. An oral account can compress these details but should retain that distinction. A listener should hear both what happened and why the preferred explanation remains provisional rather than mistaking the explanation for another measurement.

Worked report and oral explanation

Use fictional repeated density results of 2.68, 2.70 and 2.72 grams per cubic centimetre. Their mean is 2.70 and their range is 0.04. A concise results statement is: “Three determinations ranged from 2.68 to 2.72 g/cm³, with a mean of 2.70 g/cm³.” The discussion can state that repeated results show some variation but do not alone identify its source. Do not report more precision than the method supports.

Write a short methods paragraph specifying the assumed mass and volume procedure, repeated readings and unit handling. Then deliver a one-minute explanation: question, method, main result, limitation and next step. Speak the unit and explain what the result means rather than reading every number. A useful next step is checking volume measurement with a reference specimen.

Ask a listener to restate the conclusion. If they cannot distinguish the measured result from the suggested explanation, revise the transition. The finished report and oral account should communicate the same claim and uncertainty, even though the spoken version uses fewer details.

Self-check

Is passive voice always required in scientific writing?

No. Choose active or passive voice according to clarity, emphasis and responsibility.

What is the mean of 2.68, 2.70 and 2.72?

The mean is 2.70 g/cm³.

Does variation among repeats identify its cause?

No. Additional checks are needed to distinguish measurement effects from actual sample differences.

Sources and further study

Topic framework: the supplied University of Peshawar BS Geology curriculum, session 2004–05 onward. This independently authored learning resource is not affiliated with the university and does not confer a degree or accreditation.

Chapter 18 multiple choice questions

Choose one best answer for each question. Open each answer panel after making your choice.

Which sentence most clearly distinguishes a general principle from a completed action?
1. Density was always equalled by mass; the specimen weighs yesterday.
2. The specimen will have been weighed, so density might once equal volume.
3. Density and weighing are interchangeable terms in every tense.
4. Density equals mass divided by volume; the specimen was weighed three times.
Answer and explanation
D. Density equals mass divided by volume; the specimen was weighed three times. Present tense suits the general relation, while past tense describes the completed procedure.
Three density determinations are 2.68, 2.70 and 2.72 g/cm³. Which statement accurately reports both centre and spread?
1. The mean is 2.70 g/cm³ and the range is 0.02 g/cm³.
2. The mean is 2.70 g/cm³ and the range is 0.04 g/cm³.
3. The mean is 2.72 g/cm³ and the range is 0.04 g/cm³.
4. The mean is 2.68 g/cm³ and the range is 0.06 g/cm³.
Answer and explanation
B. The mean is 2.70 g/cm³ and the range is 0.04 g/cm³. The sum divided by three is 2.70, and maximum minus minimum is 2.72 − 2.68 = 0.04.
A report says repeated density values differ because of pore effects, but no pore measurements were made. How should the explanation be presented?
1. As a possible cause requiring further evidence
2. As a demonstrated mechanism established by repetition alone
3. As a replacement for reporting the measured values
4. As an exact correction that needs no method
Answer and explanation
A. As a possible cause requiring further evidence Variation is observed, but attributing it to a specific cause requires an additional test.
Where should a report primarily explain what the measured results mean and consider alternatives?
1. The list of sample identifiers only
2. The raw-data table heading only
3. Discussion
4. The reference list alone
Answer and explanation
C. Discussion Results present the evidence, while discussion interprets it and evaluates alternatives.
A one-minute oral explanation must communicate a small laboratory study. Which sequence best supports understanding?
1. Every raw value, then the title, with no conclusion
2. Question, method, main result, limitation and next step
3. A conclusion first, followed only by unrelated technical terms
4. A method name alone, with no description of the finding
Answer and explanation
B. Question, method, main result, limitation and next step The sequence connects the purpose, evidence and supported conclusion while retaining an important limitation.

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