CPD · Scientists

Designing a repeatable test

Planning an experiment someone else can repeat.

about this course

What you will be able to do

L4 PractitionerAbout 4 hours (240 minutes) of CPDSelf-study plus role-playScientists

Planning an experiment someone else can repeat.

State a question and a measure, given a topic, so it can be answered with a number.
Plan a method, given a question, with steps, controls and repeats.
Identify sources of error, given a method, listing at least 4.
Record a protocol, given a template, clear enough for another person to follow.

Task, condition and standard

Task

Plan a repeatable test by stating a question and a measure, choosing a control and repeats, listing sources of error, and writing a method another person can follow exactly.

Condition

Given a topic, a protocol template and a partner for peer checking, working in a four-hour supervised session.

Standard

Produce a testable question, a control, a measure with units, repeats for each group, at least 4 listed sources of error, and a method another person can repeat.

These courses teach process, communication and recording. They give no clinical, legal, tax, financial or engineering sign-off. A named subject expert must review every line, and you must check your own professional body's current CPD rules, before you rely on a certificate.

sessions

8 modules

Module 1 Question and hypothesis 25 min

A good question can be answered with a number
A hypothesis is a testable guess
Choose one measure

Worked example. Topic: paint drying time. Question: "Does a thin coat of paint dry to the touch faster than a thick coat?" Measure: minutes to touch-dry. Hypothesis: the thin coat dries faster. It can be answered with a number.

Practise: Practise with a case card or template for "question and hypothesis": state a question and a measure, given a topic, so it can be answered with a number.

Standard to meet. State a testable question and a hypothesis for a given topic, such as paint drying time, with one measure that can be answered with a number.

Module 2 Controls and measures 40 min

The control is the comparison without the change
Change one thing at a time
Name the measure and its unit

Worked example. Fertiliser A test: control group gets no fertiliser; same soil, light and water; only the fertiliser changes. Measure: height in cm at day 14. One change at a time keeps the comparison fair.

Practise: Practise with a case card or template for "controls and measures": plan a method, given a question, with steps, controls and repeats.

Standard to meet. Choose a control group and a measure with units for a question, and keep all conditions the same except the one thing changed.

Module 3 How many repeats 40 min

Repeats show the natural spread
More repeats give more trust
Choose the same number per group
Record an odd result; do not remove it without a stated rule

Worked example. 10 plants in each group, 2 groups = 20 plants. At 5 pots per tray that is 20 / 5 = 4 trays. Heights in group A range from 10 to 14 cm, which is the natural spread the repeats reveal.

Practise: Practise with a case card or template for "how many repeats": identify sources of error, given a method, listing at least 4.

Standard to meet. Decide how many repeats are needed for each group, and explain that repeats show the natural spread in the results.

Module 4 Writing the method 45 min

List materials, steps, measures and units
Number the steps
Write it so another lab can repeat it

Worked example. Method: 1 Fill 20 pots with 200 g of soil each (4,000 g, or 4 kg, in all). 2 Sow one seed per pot. 3 Give fertiliser A to 10 pots. 4 Water all pots 100 ml daily. 5 Measure height in cm at day 14. 6 Record every value.

Practise: Practise with a case card or template for "writing the method": record a protocol, given a template, clear enough for another person to follow.

Standard to meet. Write a method with materials, steps, measures and units that is clear enough for another person to repeat exactly.

Module 5 Peer check 35 min

Find unclear steps
Find at least four sources of error
Suggest a fix for each

Worked example. Partner reads the method and finds 4 sources of error: uneven light on the bench, pots of different sizes, height measured from different points, seedlings picked by hand (a bias). Fixes: rotate pots, one pot size, measure from the soil line, pick by random draw.

Practise: Practise with a case card or template for "peer check": record a protocol, given a template, clear enough for another person to follow. Use a new case this time (round 2).

Standard to meet. Check a partner's method against the checklist, find unclear steps and at least four sources of error, and suggest a fix for each.

Module 6 Assessment 25 min

Write a method for a new question
Include control, measure, repeats and errors
A method that cannot be repeated does not pass

Worked example. Assessment question: does a thick coat of paint dry slower than a thin one? Control: thin coat. Measure: minutes to touch-dry. Repeats: 6 panels each, 12 in all. Method has 6 steps, 4 errors listed: pass.

Practise: Practise with a case card or template for "assessment": record a protocol, given a template, clear enough for another person to follow. Use a new case this time (round 2).

Standard to meet. Create a repeatable method for a new question, with a control, a measure, repeats and listed sources of error.

Module 7 Second case: a coating and corrosion 20 min

Same planning steps, new question
Define control, measure and repeats
Predict the size of the gap

Worked example. Case card 2: does a coating cut corrosion? Control: 8 uncoated strips; test: 8 coated strips (16 in all). Measure: mass lost in mg after 30 days. Sample result: uncoated 120 mg, coated 30 mg, a gap of 90 mg or 75% less.

Practise: Practise with a case card or template for "second case: a coating and corrosion": record a protocol, given a template, clear enough for another person to follow. Use a new case this time (round 2).

Standard to meet. Plan a repeatable test for a new question, defining the control, the measure with units and the number of repeats, and calculate a sample difference.

Module 8 Teach-back and reflection 10 min

Partner repeats your method
Count the unclear steps
Rewrite and reflect

Worked example. A partner follows the 6-step method alone and asks about 2 unclear steps ("how much water?"). Learner rewrites both steps, so the method now has 0 open questions. Reflection: one source of error found late.

Practise: Practise with a case card or template for "teach-back and reflection": record a protocol, given a template, clear enough for another person to follow. Use a new case this time (round 2).

Standard to meet. Evaluate your method by asking a partner to follow it, correct each unclear step, and reflect on one source of error you would find earlier.

practice

Worked example and case cards

Worked example

Question: does fertiliser A raise plant height? Control: no fertiliser. Same soil, light, water. Measure height at day 14 in cm. Repeats: 10 plants each group. Write the method so another lab can repeat it.

Case card

a question about drying time of paint.

Case card 2

Does a coating cut corrosion? Learners define control, measure, repeats and write steps.

checks

10 check questions with model answers

Why a control?

Model answer: To compare against no treatment. (Covered in module 2: Controls and measures. To pass that module: Choose a control group and a measure with units for a question, and keep all conditions the same except the one thing changed.)

Why repeats?

Model answer: To see the spread. (Covered in module 3: How many repeats. To pass that module: Decide how many repeats are needed for each group, and explain that repeats show the natural spread in the results.)

What must the method state?

Model answer: Materials, steps, measures, units. (Covered in module 4: Writing the method. To pass that module: Write a method with materials, steps, measures and units that is clear enough for another person to repeat exactly.)

Change one thing at a time?

Model answer: Yes. (Covered in module 2: Controls and measures. To pass that module: Choose a control group and a measure with units for a question, and keep all conditions the same except the one thing changed.)

What is a control?

Model answer: The comparison without the change. (Covered in module 2: Controls and measures. To pass that module: Choose a control group and a measure with units for a question, and keep all conditions the same except the one thing changed.)

Why repeats?

Model answer: To see natural variation. (Covered in module 3: How many repeats. To pass that module: Decide how many repeats are needed for each group, and explain that repeats show the natural spread in the results.)

How detailed is a method?

Model answer: Another lab can repeat it exactly. (Covered in module 4: Writing the method. To pass that module: Write a method with materials, steps, measures and units that is clear enough for another person to repeat exactly.)

What if one sample is odd?

Model answer: Record it; do not remove without a stated rule. (Covered in module 3: How many repeats. To pass that module: Decide how many repeats are needed for each group, and explain that repeats show the natural spread in the results.)

Name one bias.

Model answer: Choosing samples by hand. (Covered in module 5: Peer check. To pass that module: Check a partner's method against the checklist, find unclear steps and at least four sources of error, and suggest a fix for each.)

A test has 20 pots and each tray holds 5 pots. How many trays are needed?

Model answer: 20 / 5 = 4 trays. (Covered in module 3: How many repeats. To pass that module: Decide how many repeats are needed for each group, and explain that repeats show the natural spread in the results.)

glossary

Words used in this course

hypothesis, control, repeat, variable, bias.

marking

How the practice and assessment are marked

Level	Meaning	Marks of 4
Secure	Meets the standard in the outcome every time, no prompts	4
Meeting	Meets the standard with one small slip, corrected when prompted	3
Developing	Meets part of the standard; needs a re-attempt	2
Not yet	Standard not met	1

Pass = average 3 or more, and no outcome at 1. You may re-attempt after feedback. The subject expert sets any stricter pass mark.

where next

Ladder L1 to L7, slide by slide with notes

Slide 1: L1 Basic: What is a fair test. Speaker note: A fair test changes one thing and keeps everything else the same. Say it with a plant example. At this level the learner knows the words question, control and measure.
Slide 2: L2 Awareness: Question and measure. Speaker note: Show a topic such as paint drying time and ask for a question that has a number as its answer. The learner at this level can state a question and name what to measure and in which unit.
Slide 3: L3 Foundation: Controls and repeats. Speaker note: Learners add a control group and repeats to a prepared question, such as 10 plants per group. They follow a template and see why one sample cannot show the natural spread.
Slide 4: L4 Practitioner: Plan a repeatable test. Speaker note: This course sits here. The learner states a question and measure, plans steps with a control and repeats, lists at least four sources of error, and writes a protocol another person can repeat.
Slide 5: L5 Specialist: Hard designs and bias. Speaker note: The specialist handles designs with several groups, picks samples by random draw to avoid bias, and judges how many repeats are enough. They coach others in spotting hidden changes between groups.
Slide 6: L6 Advanced: Protocols across a team. Speaker note: The advanced worker writes shared protocols, reviews team methods for unclear steps, and keeps records so results can be re-checked. Talk about why two labs got different answers from the same words.
Slide 7: L7 Super expert: A testing standard for the lab. Speaker note: The super expert sets the lab's method standard: templates, review steps, training and measures such as how often a method is repeated by someone else with the same result. They decide what repeatable means.

This course sits at L4 Practitioner. Credits stack; aligned with, not accredited by, any framework.

jobs this leads to

Where this takes you

Laboratory assistant
Research assistant
Laboratory technician
Quality control technician
Field data collector

assessment and certificate

How you are checked

Each outcome is checked against its standard with a checklist or a short test. A digital CPD record shows the hours. Keep evidence in My page. Aligned with common CPD practice; not accredited. Learners check their own body's rules.

ten locations and global

Your place

Use your own body's forms, units and currency. Local professional bodies set the rules for CPD hours; check them first.

India (Bengaluru)

Language: English, Hindi, Kannada. Personal data: Digital Personal Data Protection Act 2023. Credit and levels: National Skills Qualifications Framework (NSQF) and the national credit framework.

Netherlands (Eindhoven area)

Language: Dutch, English. Personal data: EU GDPR (Dutch: AVG), supervised by the Autoriteit Persoonsgegevens. Credit and levels: the Dutch qualification framework (NLQF) linked to the European Qualifications Framework.

UAE (Dubai and Abu Dhabi)

Language: Arabic, English. Personal data: Federal Decree-Law No. 45 of 2021 (personal data protection). Credit and levels: the emirate education and training regulators (for example KHDA in Dubai) and the national qualifications framework.

Brazil (Sao Paulo)

Language: Portuguese (Spanish and English support). Personal data: LGPD (Lei Geral de Protecao de Dados). Credit and levels: the national technical-education catalogue and the national S-system training bodies.

Canada (Toronto)

Language: English, French. Personal data: PIPEDA, with provincial rules where they apply. Credit and levels: the provincial colleges framework and the national credential-recognition guidance.

United States

Language: English, Spanish. Personal data: state privacy laws (for example California), and COPPA for children under 13. Credit and levels: state and community-college credit systems.

Singapore

Language: English, Mandarin, Malay, Tamil. Personal data: Personal Data Protection Act (PDPA). Credit and levels: the Singapore national skills frameworks and the national credit system.

Australia

Language: English. Personal data: the Privacy Act 1988 and the Australian Privacy Principles. Credit and levels: the Australian Qualifications Framework (AQF) levels.

Hong Kong (Eastern Asia)

Language: Chinese (Cantonese, Mandarin), English. Personal data: the Personal Data (Privacy) Ordinance. Credit and levels: the Hong Kong Qualifications Framework.

Georgia and Israel (Western Asia)

Language: Georgian, Hebrew, Arabic, English. Personal data: the personal data law of the country where the learner lives. Credit and levels: the national qualifications framework of that country.

Cayman Islands (Caribbean)

Language: English. Personal data: the Data Protection Act. Credit and levels: the local education and training framework.

Mexico

Language: Spanish, English. Personal data: the federal law on personal data held by private parties. Credit and levels: the national competency certification system and the education ministry levels.

Draft

Draft CPD course. It opens only after final checks. No fee is shown.

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