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D1.1 · Design ethical questionnaires or experiments for one-variable data

Learn to design ethical questionnaires or experiments for one-variable data through clear examples and targeted practice.

Ontario Grade 11 Mathematics

Data Management

MBF3C study topic D1.1: collecting useful data about one variable

A school wants to learn about students’ daily travel time, or a community group wants to compare how long two routes take to walk. In both cases, the results depend on how the information is collected. A confusing question, an unfair choice of participants, or an inconsistent procedure can lead to misleading data. In this lesson, a variable means a characteristic that can have different values, such as travel time in minutes. One-variable data means that each response or observation records one main characteristic. A questionnaire asks people for information. An experiment uses a planned procedure to observe or measure what happens. Both should be designed with care for the people taking part and for the quality of the data.

What you will learn

Identify the one variable a questionnaire or experiment is intended to measure.
Design clear, neutral questions and consistent measurement procedures.
Recognize privacy, consent, safety, and fairness concerns when collecting data.
Explain how a design choice can make results less useful or less trustworthy.

1. Start with the purpose and the variable

Before writing a question or planning a procedure, state what you want to find out. Then name the one variable you will record. This step matters because it keeps the data collection focused. If your purpose is to describe students’ travel time to school, the variable is travel time, not students’ opinions about transportation or the distance they travel.

Decide who the information is about. This group is the population. For example, the population might be all students at one school. If you collect responses from only a few students, those students are your participants. The group of participants should give you useful information about the population. If you ask only students who arrive by bus about travel time, you leave out students who walk, cycle, or travel by car.

Choose how the variable will be recorded. A numerical variable can be recorded as a number, such as minutes. A category variable can be recorded as a label, such as the main way a student travels. Use one consistent unit or set of response categories. Clear recording rules make it easier to compare responses and reduce avoidable errors.

A questionnaire is often suitable for information people can report, such as how many minutes they usually spend travelling. An experiment is suitable when a planned, safe procedure can produce a measurement, such as the time needed to complete a short task. Do not call a questionnaire an experiment: participants report information in a questionnaire, while an experiment includes a procedure that is carried out.

State the purpose before collecting data.
Name one main variable and decide how to record it.
Choose participants and a method that fit the population and purpose.

2. Make questionnaires clear, fair, and respectful

A good questionnaire asks each person for information about the same variable in a clear way. Use familiar words and a time frame that people can understand. “About how many minutes does your usual trip to school take?” is more focused than “Tell us about your commute.” The first question identifies what to report and gives a unit.

Avoid leading questions. A leading question suggests the answer the writer wants. For example, “Don’t you agree that the new schedule is much better?” pressures the respondent toward a positive answer. A neutral version asks, “How would you rate the new schedule?” and offers balanced choices. Response choices should cover likely answers and should not overlap. If a person could reasonably fit two choices, revise the choices.

Consider ethics, meaning responsible and respectful treatment of participants. Tell people why you are collecting information and how it will be used. Participation should be voluntary: people can choose whether to take part and should not be pressured. Ask only for information needed for the purpose. Protect privacy by avoiding names or other identifying details when they are not needed, and explain who can see the responses. Do not promise complete anonymity if answers can be connected to a person.

Think about who might be left out or uncomfortable. A question about personal finances, health, or family circumstances may be sensitive. If that information is not needed, do not ask for it. If people may skip a question, state that clearly. Before using the questionnaire, test it with a small number of people. Ask whether the wording and choices made sense, then revise confusing parts.

Use neutral wording, a clear time frame, and one variable per question.
Make response choices understandable and non-overlapping.
Explain purpose, voluntary participation, privacy, and how results will be used.

3. Plan experiments with consistent and safe procedures

An experiment needs a written procedure that participants can follow in the same way. State what each participant will do, what will be measured, and the unit for the measurement. If the variable is completion time, decide when timing starts and stops. Without shared rules, differences in the results might come from different instructions rather than from the participants’ performance.

Keep the procedure fair. Give participants the same instructions and comparable conditions when the purpose is to collect measurements that can be compared. Use suitable equipment and check that it works. Record results in the same units and with the same level of precision. For example, do not record some times to the nearest second and others to the nearest minute without a reason.

Safety and consent come first. Describe what the activity involves, check for avoidable risks, and do not ask people to do something unsafe or humiliating. Participants should know what they are agreeing to and be free to stop. If a procedure could cause harm or discomfort, choose a safer approach or do not run it. A useful data set does not justify treating participants carelessly.

A small trial run can reveal unclear instructions, timing problems, or equipment issues before the full data collection. It also gives the designer a chance to check whether the planned measurement really matches the purpose. Keep the trial procedure simple and revise it before collecting the main set of data.

Write steps so every participant experiences the same procedure.
Define the measurement, timing rules, units, and recording method.
Check consent and safety before carrying out an experiment.

4. Review the design before collecting data

A final review can catch problems early. Ask whether the design measures the variable named in the purpose, whether the participants are relevant, and whether the instructions are clear. Check that the collection method does not unnecessarily expose personal information or exclude a group whose information matters.

Bias is a systematic influence that can push results in one direction. A leading question can create response bias because wording influences answers. Asking only people who are easy to reach can create an unrepresentative set of responses. An experiment can also be unfair if some participants receive different instructions or use different equipment. Naming these risks does not guarantee perfect data, but it helps you improve the design.

A practical design record can include the purpose, population, variable, participants, question or procedure, response or measurement choices, privacy plan, and safety steps. This record helps another person understand how the data were collected. It also makes it easier to explain limits in the results without claiming that the data say more than they do.

Check relevance, clarity, fairness, privacy, and safety before collecting data.
Look for wording or selection choices that could systematically affect responses.
Describe the method so another person can understand the data collection.

Design review at a glance

Design feature	Question to ask	Example for travel time
Purpose and variable	What one characteristic will be recorded?	Usual one-way travel time
Clear collection method	Will everyone understand the question or steps?	Report a number of minutes
Fairness	Could wording or participant choice tilt results?	Invite students using different travel modes
Ethics	Are participation, privacy, and safety addressed?	Explain use; avoid unnecessary names

Worked example

Example 1: Improve a questionnaire

A student council wants to describe the usual one-way travel time to school for students at a secondary school. Its draft question is: “How long is your long and frustrating trip to school, and why is the bus so slow?” Redesign the question and identify ethical and data-quality choices.

Set the purpose
The purpose is to describe travel time for students at the school. The variable is the number of minutes for a usual one-way trip. Asking why a bus is slow would collect opinions and assumes that the respondent takes a bus.
Remove leading wording
Words such as “long,” “frustrating,” and “slow” can influence a response. Ask neutrally and specify the trip and unit so students know what to report.
Protect participants and include relevant students
Ask students from different travel modes, not just bus riders. Do not ask for names unless they are needed. Explain the purpose, make participation voluntary, and say who will see the responses.

Answer: A suitable item is: “About how many minutes does your usual one-way trip to school take? Enter a number of minutes. You may skip this question.” Invite students who use different travel modes to participate. Explain how responses will be used and limit access to them.

Check: The revised item records one variable, travel time, rather than asking about both time and opinions. Its wording does not assume that the trip is frustrating or that the student takes a bus.

Worked example

Example 2: Plan a simple experiment

A class wants to collect one-variable data about how long students take to walk a marked 20-metre distance at a comfortable pace. Design an ethical and consistent procedure.

Name the measurement
The variable is the time, in seconds, for one walk over the marked distance. Everyone should use the same start and finish points, so each recorded value refers to the same task.
Set shared instructions
Mark the same route for every participant. Explain where to start and stop, and ask each person to walk at a comfortable pace. Use the same timing rule for everyone. This makes the measurements more comparable.
Check consent and safety
Explain the activity and ask for volunteers. Let participants stop or decline without pressure. Check that the route is clear and safe, and avoid recording names if they are not needed.
Record consistently
Use the same timer and record each result in seconds using the same rounding rule. A short trial run can show whether the route, instructions, and timing method are clear before the class collects its main data.

Answer: Invite volunteers, explain the purpose, and use a clear, safe 20-metre route. Give everyone the same comfortable-pace instruction and timing rules. Measure one walk per participant, record the time in seconds using the same rounding rule, and do not attach names unless necessary.

Check: Each result is one measurement of the same variable under the same stated procedure. Consent, a safe route, and limited identifying information support respectful data collection.

Common mistakes and how to avoid them

Combining two questions, such as asking for travel time and a reason in the same item.

Correction: Keep the collection focused on the one variable named in the purpose. If another variable is needed, design and justify a separate item.

Using wording that suggests a preferred answer.

Correction: Remove judgmental words and ask in a neutral way.

Assuming that a measurement is fair because everyone takes part.

Correction: Also check that instructions, conditions, units, and recording rules are consistent.

Collecting names or sensitive details just in case they are useful later.

Correction: Collect only what the purpose requires and explain how responses will be protected and used.

Lesson summary

Begin with a clear purpose and identify one main variable.
Choose a suitable questionnaire or experiment and define how responses or measurements will be recorded.
Use neutral wording or consistent procedure steps so the method does not push results in a particular direction.
Respect participants through voluntary participation, privacy, clear information, and safe procedures.
Review who is included and how data are collected before using the design.

Check your understanding

Question 1

A survey asks, “How many minutes does your usual trip to school take?” What is the main variable?

The student’s travel time in minutes
The student’s opinion of school
The student’s name
The number of buses at the school

Show answer and explanation

The student’s travel time in minutes

The question asks each student to report the time for a usual trip, measured in minutes.

Question 2

Which question is the most neutral way to ask about a new lunch schedule?

Why is the new lunch schedule so inconvenient?
Don’t you agree the new lunch schedule is better?
How would you rate the new lunch schedule?
Why do students dislike the new lunch schedule?

Show answer and explanation

How would you rate the new lunch schedule?

The rating question does not assume that the schedule is good or bad. The other choices suggest an opinion.

Question 3

A class times volunteers completing the same safe task. Which design choice best supports comparable measurements?

Give each person different instructions
Use the same timing rules and record every result in seconds
Record names even when they are not needed
Let each participant choose a different task

Show answer and explanation

Use the same timing rules and record every result in seconds

Shared timing rules and units help ensure that each recorded value represents the same measurement.

Key terms

Variable: A characteristic that can take different values, such as travel time.
Population: The full group that a data collection is intended to describe.
Participant: A person who takes part in a questionnaire or experiment.
Bias: An influence in the design or collection method that can push results in a particular direction.
Voluntary participation: Taking part by choice, without pressure, and being able to decline or stop.

Continue through MBF3C

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About this lesson

Published by DoAssignment. This AI-assisted lesson follows Ontario Grade 11 Mathematics (MBF3C), expectation D1.1. It is a study resource, not an official curriculum publication.

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