🔬 ScienceGrade 5Lesson 7
← Back🔒 PDF with full access

Ask Testable Questions

Lesson preview: the Mini Lesson and Vocabulary are open to everyone. Guided practice, exercises, the parent checklist and the printable PDF worksheet come with full access (free 7-day trial or membership).

Learning Objectives

  • 1Explain what makes a question testable
  • 2Tell the difference between testable and opinion questions
  • 3Rewrite vague questions as measurable, testable ones
  • 4Choose the variable you would measure to answer a question
📘

Mini Lesson

Every science investigation begins with a question. But not every question can be answered by an experiment. A testable question is one you can answer by measuring or observing something carefully. Learning to ask testable questions is the first skill of a scientist.

What Makes a Question Testable?

  • You can change one thing (a variable) to see what happens.
  • You can measure or count the result with a tool — a ruler, scale, timer, or thermometer.
  • Two people doing the same test would get similar results.
  • It does not depend on personal taste or feelings.

Testable vs. Not Testable

  • Testable: "How does temperature affect how fast sugar dissolves in water?" — you can measure time and temperature.
  • Not testable: "Is sugar yummy?" — taste is an opinion, not a measurement.
  • Testable: "Which paper towel brand absorbs the most water?" — you can measure water in milliliters (1 mL ≈ 1/5 teaspoon).
  • Not testable: "Which paper towel is the best?" — "best" depends on what you mean.

Turning a Vague Question into a Testable One

  1. Spot the opinion or vague word ("best", "good", "fun", "nicer").
  2. Replace it with something you can measure (height, time, temperature, distance, count).
  3. Name the one thing you will change (the independent variable).
  4. Name the one thing you will measure (the dependent variable).
Testable vs. Not TestableTestable vs. Not TestableTestableNot TestableHas a variable to changeYou can measure resultRepeatable by anyone"How does X affect Y?"Based on opinionNo way to measureUses "best" or "fun""Which one is nicer?"A testable question can be answered with dataAn opinion question cannot be measured
From Vague to TestableFrom Vague to Testable1. Vague question"Which plant is the best?"2. Add a measurement"Which plant grows the tallest?"3. Testable question"How does sunlight affect theheight of bean plants in 14 days?"Name what you change and what you measure
💡

Tip: if your question uses "best", "good", "fun", or "nicer", it is probably an opinion. Replace those words with something you can count or measure (height in cm — about 0.4 in each, time in seconds, mass in grams — about 0.035 oz each).

Vocabulary
testable question
A question you can answer by measuring or observing something.
opinion question
A question that depends on personal taste or feelings, not measurement.
variable
Something in an experiment that can change or be measured.
measurable
Able to be counted or measured with a tool like a ruler, timer, or scale.
observation
Information you collect using your senses or instruments.
Free · 7 days · No credit card

Unlock the full HSEA system for 7 days.

Add your first kid profile and your 7 days start: every lesson in every grade, saved progress for each child. Nothing to set up, no card required, nothing to cancel.

  • ✓ All 1,680 lessons, Grades 1–6, every subject
  • ✓ Profiles + saved progress for every kid
  • ✓ Printable lessons with answer key
Start your 7-day free trial →
Already convinced? See full membership plans →
← Lesson 6: Science Journal Best PracticesLesson 8: Peer Review & Conclusions →