GAC Science · ⁨Khoa học GAC⁩

From readings to an investigation report

A paper holds more water in one comparison. What should its report actually claim? A strong report lets the reader trace the conclusion back to the method and readings. These extra notes develop the reporting outcome alongside the original GAC013 handout. Your teacher's actual brief sets the required structure and assessment criteria.

Plan, conduct and record

A research question 研究问题 identifies what you want to find out. For example: which of two paper types retains more water under the stated procedure? A hypothesis 假设 gives a testable prediction or explanation. Predict a difference between paper types, then identify which readings could challenge that prediction.

Specify the independent variable 自变量, measured response and relevant controlled conditions before starting. Here, paper type is the independent variable. Retained-water mass, measured as wet mass minus dry mass, is the dependent variable 因变量. Use fresh squares with the same area, the same immersion and draining times, and the same checked balance. Do not squeeze only one paper type. State how the order of trials will be chosen. A change in procedure must be recorded; it cannot be repaired by hiding a reading.

Obtain teacher agreement on a safe, permitted method before conducting any practical activity. Keep a dated record of materials, instructions, units, readings and changes to the plan. Record what happened, including unexpected observations and missing readings. Do not invent completed trials.

Show the evidence and the calculation

The following table repeats the original handout's fictional data. It is written practice, not a new completed investigation.

A mean summarises the readings. Show enough calculation for a reader to check it:

The difference between these means is $4.2-3.0=1.2\ \text{g}$. Each paper's readings span 0.4 grams. This spread is not automatically the full measurement uncertainty 测量不确定度. The balance, timing and draining procedure may also contribute to uncertainty. No statistical test 统计检验 or confidence level 置信水平 has been supplied; do not invent one.

Write a conclusion that fits the test

A conclusion 结论 answers the research question using the recorded evidence. For these fictional readings, B retained more water on average under the supplied conditions. The observed difference is 1.2 grams. Both types show variation between trials.

Do not write “B is best for every task”. Strength, price and performance in other uses were not tested. Do not claim that repeats repaired an unequal procedure. Repeats help examine variation, not remove systematic bias 系统性偏差. A limitation should identify a specific problem and explain its effect on the interpretation. An improvement should address that problem, not promise perfect results.

Worked evaluation. One trial used a longer draining time for A. Its reading may be lower because of the changed draining procedure, rather than paper type alone. Keep the original record and flag the departure from the plan. A later permitted trial using the agreed timing can add evidence; it does not make the earlier event disappear.

Organise and reference the report

A reference 参考文献 identifies where a borrowed fact, idea or image came from. Use the reference style required by your brief. Keep enough information to locate each source. Mark supplied case data as supplied data. Distinguish research you propose from work actually completed. Copying a claim from a website is not independent confirmation of it. Check who produced the source, which evidence it provides and whether it addresses your question.

Practice and explained answers

1. Identify the changed variable and measured response.
2. Why do three repeats not repair squeezing only A?
3. Calculate the mean difference and each set's range.
4. Write a conclusion without a universal product claim.
5. How should a report describe a test that is only planned?

Answers.

1. Change paper type; measure wet mass minus dry mass, in grams.
2. Squeezing changes another condition. Repeats do not isolate paper type.
3. Mean difference: 1.2 g. Each range: 0.4 g, not the whole uncertainty.
4. B retained more water under these conditions; other properties were not tested.
5. Label it as planned; it adds no observations or confirmation until performed.

A team investigation needs more than divided writing

Two teams describe the same pond. One records where and when observations were made; the other combines undated photographs and a website's general statements. Which report lets a reader check its conclusions? This supplement develops the collaborative investigation and Internet-research outcomes alongside the original GAC023 handout. Follow the current centre brief for the required task, methods and assessment criteria.

Agree a question, method and team record

A collaborative investigation 合作探究 shares a scientific task with clear responsibilities and a common method. Choose a narrow question that permitted observations can address. For example: how does the proportion of ground covered by the selected plant differ between two accessible, teacher-approved areas? This is a comparison of coverage, not automatically a test of growth rate or proof of the cause of a difference.

A sampling method 取样方法 specifies how observations are selected. Define the areas and observation period before collecting records. Use the same frame size and counting rule at both areas. Select positions by an agreed method, rather than choosing only attractive examples. Random selection within an accessible area can reduce deliberate selection, but cannot represent places excluded from that area. Keep repeats 重复测量 distinct from revisiting the exact same record: ten photographs of one patch are not ten independent patches.

Agree which member records location and time, which estimates coverage and which checks the entries. Rotate or check roles if different observers could systematically use different rules. A common recording sheet needs labels, units, the selection method and any deviations. Keep each original record and identify its observer. Resolve a disagreement by checking the agreed rule and evidence; do not replace an inconvenient result with the group average.

Obtain teacher agreement before fieldwork. Respect access restrictions, weather and local site rules. Use permitted observations without entering unsafe water or collecting unknown organisms or chemicals. A report about a proposed investigation must call it proposed. Research does not replace required fieldwork.

Analyse a supplied case without inventing causes

The following supplied data 给定数据 are fictional practice records, not a completed field investigation. Both areas use the same coverage rule and frame size. Each row represents a different selected position.

Calculate each mean from its three records. The mean difference is 50 − 30 = 20 percentage points 百分点. Each area's range is twenty percentage points. A difference of twenty percentage points is not the same statement as a twenty-percent relative increase: relative to A's mean, the increase would be 20 ÷ 30 × 100%, approximately 66.7%.

A suitable conclusion 结论 is: in the supplied samples, mean coverage was greater in B, with variation within both areas. Three samples do not establish all seasons or every part of the pond. The table gives no light, soil, water or time-series measurements. It therefore cannot show that pollution caused the difference or that a plant grew faster. Coverage also does not measure species richness. Identify the additional question and measurements needed rather than inventing an explanation.

Describe the local environment through different evidence

A physical feature 物理特征 concerns conditions such as layout, slope, shade or water movement. A chemical feature 化学特征 concerns substances and quantities, such as a dated concentration measured by a stated method. A biological feature 生物特征 concerns organisms, their distribution and relationships. Keep the categories connected without treating one as proof of another.

For a local environment report, use a labelled location description and dated records. State which observations your team made and which came from another source. An organism photograph can support an identification within its limits; it cannot establish drinking-water safety. A chemical result without a date, unit or method may be unsuitable for the comparison. If the assignment uses secondary information only, state that limitation rather than presenting it as your own measurement.

Research online and make the report traceable

A secondary source 二手资料 reports information collected or interpreted by someone else. Check the producer, date, purpose, method and relevance to your question. Prefer the original measurement record or research report when available. A search-result preview does not replace reading the source. Two websites repeating one report are not two independent observations.

Keep a source log as you research: author or organisation, title, date, address, the exact claim used and its limits. Use the reference style required by your brief. A citation 引用标注 links a claim to its source; the reference list gives the details needed to locate it. Explain the idea in your own words while citing it. Cite borrowed images and respect their permitted use. Do not make a missing date, method or author up.

Organise the report around question and background, method and team responsibilities, results, discussion and conclusion, and references. Distinguish observation from explanation, and your records from published background. Show checked calculations, units and labelled tables. Discuss a specific limitation and a matching improvement. A reflection should identify each person's actual contribution and a concrete coordination issue; equal-length paragraphs do not demonstrate equal participation.

Practice and explained answers

1. Why are ten photographs of one patch not ten independent patches?
2. Calculate the mean difference for the supplied coverage data, with its unit.
3. Can these data prove pollution caused the coverage difference? Explain.
4. What must accompany a borrowed chemical measurement?
5. Two sites repeat one report. How many independent records does this establish?
6. What should a team do when its members disagree about one coverage entry?

Answers.

1. The sampled location has not changed; extra photographs do not broaden sampling.
2. 50 − 30 = 20 percentage points, not twenty percent relative to A.
3. No. Pollution was not measured, and alternative explanations remain.
4. Its source, date, unit, method and relevant limitations.
5. One underlying report; repetition alone adds no independent observation.
6. Check the shared rule and evidence; retain the original record and correction trail.