Scientific Communication: Reports, Tables, and Graphs
Yaritza heats water in her kitchen at home and writes down the temperature every minute. If she only writes loose numbers on a sheet of paper, no one else will be able to understand them, not even herself a month from now. Science doesn't end with the experiment: you have to communicate what was done and what was found, so that anyone can repeat it and check it.
The parts of a report
You read on social media that a plant grows twice as much if you put merengue on it all day, but they don't say which plant, how many times they measured it, or what instrument they used. Can you believe it? For a result to be reliable, the report must tell how it was obtained. This is also how you spot pseudoscientific information: if there is no data and no procedure, be suspicious.
A scientific report has these sections, but they are out of order: conclusions, aim and hypothesis, results, equipment and procedure. Put them in order and write one…
A scientific report has these sections, but they are out of order: conclusions, aim and hypothesis, results, equipment and procedure. Put them in order and write one sentence about what is included in each section.
State which section of the report each sentence belongs to: a) "We used two beakers, a measuring cylinder, a thermometer and a stopwatch." b) "The salt dissolved faster…
State which section of the report each sentence belongs to:
- a) "We used two beakers, a measuring cylinder, a thermometer and a stopwatch."
- b) "The salt dissolved faster in hot water."
- c) "We wanted to test whether water temperature affects the dissolving of salt."
- d) "The results support our initial hypothesis."
Scientists publish their experiments by describing the procedure in full detail: quantities, units, and steps followed. a) Explain why they do this, considering other…
Scientists publish their experiments by describing the procedure in full detail: quantities, units, and steps followed.
- a) Explain why they do this, considering other teams that might want to repeat the experiment.
- b) What problems would a report have if it only said "we added a little salt and heated for a while"? Give two specific examples of missing information.
Data tables
You find a paper with the pairs "0 - 15," "5 - 30," and "10 - 45." Are they minutes and degrees, or seconds and meters? Data has to be organized so that it can be understood on its own.
Tables can be made by hand or in a spreadsheet on a computer or a cell phone, which also lets you draw the graph with one click.
Aitana heats water and records the temperature every minute: at minute $0$, $20\ ^\circ\text{C}$; at minute $1$, $30\ ^\circ\text{C}$; at minute $2$,…
Aitana heats water and records the temperature every minute: at minute $0$, $20\ ^\circ\text{C}$; at minute $1$, $30\ ^\circ\text{C}$; at minute $2$, $40\ ^\circ\text{C}$; and at minute $3$, $50\ ^\circ\text{C}$.
- a) What was the temperature of the water at minute $2$?
- b) How much does the temperature increase each minute?
In a report table, the first column is titled simply "time" and the second simply "temperature". Rewrite both headings as they should appear in a scientific report, with…
In a report table, the first column is titled simply "time" and the second simply "temperature". Rewrite both headings as they should appear in a scientific report, with the quantity and unit in brackets.
In an experiment on dissolving sugar, the following unordered data was obtained: at $40\ ^\circ\text{C}$ it takes $20\ \text{s}$; at $20\ ^\circ\text{C}$ it takes…
In an experiment on dissolving sugar, the following unordered data was obtained: at $40\ ^\circ\text{C}$ it takes $20\ \text{s}$; at $20\ ^\circ\text{C}$ it takes $60\ \text{s}$; at $60\ ^\circ\text{C}$ it takes $10\ \text{s}$. Organise them in a two-column table and write the heading for each column showing its quantity and unit.
A classmate hands in this table from a water heating experiment: the first column reads "time ($\text{min}$)" with values $0$, $5$ and $10$, and the second reads simply…
A classmate hands in this table from a water heating experiment: the first column reads "time ($\text{min}$)" with values $0$, $5$ and $10$, and the second reads simply "temperature" with values $20$, $35$ and $50$.
- a) What is missing from the second column heading?
- b) Why is this mistake important?
- c) Rewrite the column heading correctly.
Graphs
You see a line that rises quickly, but the axes only have numbers. What is missing to know what is really happening?
This is the graph of Yaritza's water: it rises 10 °C every minute, which is why the points line up.
Interpreting the shape of the graph
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A slanted line indicates that the quantity is changing. The steeper it is (the greater the slope), the faster it changes.
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A horizontal line indicates that it doesn't change. On a temperature-time graph of ice being heated, the flat section at 0 °C is the change of state: the heat is used to melt the ice, not to raise the temperature.
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On a distance-time graph, the steepest section is where the speed is highest.
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If a graph is a straight line, the quantity always changes at the same rate, and that lets you predict: if a faucet fills 50 mL every hour, in 8 hours there will be 400 mL, as long as the rate stays the same.
A graph shows the height of a sunflower during the first three weeks of its growth. Look at the graph: a) How tall was the sunflower in week $2$? b) How much did it grow…
A graph shows the height of a sunflower during the first three weeks of its growth. Look at the graph:
- a) How tall was the sunflower in week $2$?
- b) How much did it grow between week $1$ and week $3$?
List the three things every graph must have to be understandable: a title, the label of the horizontal axis (with its quantity and its unit) and the label of the…
List the three things every graph must have to be understandable: a title, the label of the horizontal axis (with its quantity and its unit) and the label of the vertical axis (with its quantity and its unit). Then, explain why drawing the line is not enough.
A graph shows how a cup of tea cools down: when poured it is at $70\ ^\circ\text{C}$; after $10$ minutes, at $50\ ^\circ\text{C}$; and after $20$ minutes, at…
A graph shows how a cup of tea cools down: when poured it is at $70\ ^\circ\text{C}$; after $10$ minutes, at $50\ ^\circ\text{C}$; and after $20$ minutes, at $40\ ^\circ\text{C}$. Observe the graph:
- a) How much did the temperature drop between minute $10$ and minute $20$?
- b) Calculate how much it dropped in the first $10$ minutes and state in which of the two intervals it dropped more.
A graph shows the temperature of a glass of ice being heated: it rises from $-5\ ^\circ\text{C}$ to $0\ ^\circ\text{C}$, remains flat at $0\ ^\circ\text{C}$ for a while,…
A graph shows the temperature of a glass of ice being heated: it rises from $-5\ ^\circ\text{C}$ to $0\ ^\circ\text{C}$, remains flat at $0\ ^\circ\text{C}$ for a while, and then rises again, as shown in the graph.
Interpret what is happening to the ice along the horizontal section and explain why the temperature does not rise there.
Maximum, minimum, and comparing data
Four friends run the 100 m at school. Who was the fastest? To decide, you have to compare the maximum and minimum values, and remember what each one means for that quantity.
Explain in your own words the advantage of a data table and the advantage of a graph. Give an example of when you would use each.
Explain in your own words the advantage of a data table and the advantage of a graph. Give an example of when you would use each.
Here are the times for the $100\ \text{m}$ sprint of four friends: $14$, $16$, $15$ and $13$ seconds. a) State the maximum and minimum values. b) Who ran faster, the…
Here are the times for the $100\ \text{m}$ sprint of four friends: $14$, $16$, $15$ and $13$ seconds.
- a) State the maximum and minimum values.
- b) Who ran faster, the person with the maximum time or the minimum time? Explain why.
You want to see at a glance whether the swimming pool water heats up faster and faster throughout the day. What would you present: a table or a graph? Justify your…
You want to see at a glance whether the swimming pool water heats up faster and faster throughout the day. What would you present: a table or a graph? Justify your choice.
Results, discussion, and conclusions
You already have the table and the graph. The most important part is missing: saying in words what they mean.
A table reads: after $1$ minute there is $10\ \text{g}$ of dissolved salt; after $2$ minutes, $20\ \text{g}$; and after $3$ minutes, $30\ \text{g}$. Write a one- or…
A table reads: after $1$ minute there is $10\ \text{g}$ of dissolved salt; after $2$ minutes, $20\ \text{g}$; and after $3$ minutes, $30\ \text{g}$. Write a one- or two-sentence conclusion summarizing what happens.
Convert these notes into the results section of a report, written in two or three complete sentences: "puddle in the sun: dries in $25$ minutes; puddle in the shade:…
Convert these notes into the results section of a report, written in two or three complete sentences: "puddle in the sun: dries in $25$ minutes; puddle in the shade: dries in $60$ minutes".
A distance-time graph of Vega's bike ride has two sections: in the first section she covers $4\ \text{km}$ in $20$ minutes, and in the second, $6\ \text{km}$ in $20$…
A distance-time graph of Vega's bike ride has two sections: in the first section she covers $4\ \text{km}$ in $20$ minutes, and in the second, $6\ \text{km}$ in $20$ minutes. Observe the graph:
- a) In which section was she travelling faster?
- b) How can you tell from the graph? Think about the gradient of each section.
A graph in a report has no title, the horizontal axis only says "time" without a unit, and the vertical axis has no label at all. a) Point out all the mistakes. b)…
A graph in a report has no title, the horizontal axis only says "time" without a unit, and the vertical axis has no label at all.
- a) Point out all the mistakes.
- b) Rewrite how that graph should be presented (full title and labels) if it shows how water is heated over $10$ minutes.
- c) Explain the problem with interpreting a graph without units.
The weight table for a kitten reads: at $1$ month, $1\ \text{kg}$; at $2$ months, $2\ \text{kg}$; at $3$ months, $1.5\ \text{kg}$; and at $4$ months, $4\ \text{kg}$. a)…
The weight table for a kitten reads: at $1$ month, $1\ \text{kg}$; at $2$ months, $2\ \text{kg}$; at $3$ months, $1.5\ \text{kg}$; and at $4$ months, $4\ \text{kg}$.
- a) Which data point seems incorrect? Why?
- b) Propose an explanation for how this error might have occurred.
- c) What should the team do before drawing conclusions?
a) You want to compare the monthly rainfall in your town throughout the year. b) You want to show how the temperature of an oven changed over one hour. For each case,…
- a) You want to compare the monthly rainfall in your town throughout the year.
- b) You want to show how the temperature of an oven changed over one hour.
For each case, choose the most appropriate form of representation (table, bar chart or line graph) and justify your choice.
In an experiment, the hypothesis was: "a drink can cools down faster in ice than in the fridge". The data (both cans start at the same temperature): in ice it drops to…
In an experiment, the hypothesis was: "a drink can cools down faster in ice than in the fridge". The data (both cans start at the same temperature): in ice it drops to $10\ ^\circ\text{C}$ in $15$ minutes; in the fridge, in $40$ minutes. Write the conclusions section: state whether the hypothesis is confirmed, support your answer with the data, and explain the result in one sentence.
A graph compares how water cools down in a metal glass and in a plastic glass: the water in the metal glass drops from $60\ ^\circ\text{C}$ to $30\ ^\circ\text{C}$ in…
A graph compares how water cools down in a metal glass and in a plastic glass: the water in the metal glass drops from $60\ ^\circ\text{C}$ to $30\ ^\circ\text{C}$ in $10$ minutes; the water in the plastic glass drops from $60\ ^\circ\text{C}$ to $45\ ^\circ\text{C}$ in the same time. Look at the graph:
Write a three- or four-sentence analysis for the report: which one cools down faster, how this can be seen on the graph, and what conclusion you draw about the materials.
A report has the objective ("check if light affects seed germination"), the hypothesis ("seeds germinate faster in the light"), and the results (in the light they…
A report has the objective ("check if light affects seed germination"), the hypothesis ("seeds germinate faster in the light"), and the results (in the light they germinated in $4$ days; in the dark, in $7$ days).
- a) Write the conclusions section.
- b) State what other important section is missing from the report and what it should include.
A dripping tap fills a glass very regularly: after the first hour there is $50\ \text{mL}$; after the second, $100\ \text{mL}$, and after the fourth, $200\ \text{mL}$.…
A dripping tap fills a glass very regularly: after the first hour there is $50\ \text{mL}$; after the second, $100\ \text{mL}$, and after the fourth, $200\ \text{mL}$.
- a) Predict how much water there will be after $8$ hours.
- b) Explain how you calculated it.
- c) Is your prediction completely certain? Mention one thing that could cause it to fail.
Back to the beginning: for anyone to understand Yaritza's experiment, she must organize her measurements in a table with complete headers ("time (min)" and "temperature (°C)"), draw the graph with a title and labeled axes, and write up her results, her discussion, and her conclusions.