How to Make Testable Questions for Science

What are testable questions? In fourth and fifth grade science, kids learn that it compares only one variable. Furthermore, it allows them to predict, observe, and measure.

Ms. Sneed Discusses Science Practices

At the beginning of the school year, our favorite fourth grade teacher sat at the side table with her student teacher. “Today,” she said, “we’ll begin talking about science practices.”

“Like the scientific method?” asked Mr. Grow.

Ms. Sneed looked at him with a gentle smile. “Sort of. Since the dawn of the Next Generation Science Standards, things have changed. Now educators understand the need for a set of flexible science practices. Gone are the days of one rigid method.”

After pausing to think, Mr. Grow responded. “Actually, I get it. Before, we had only experiments and non-experiments. If it didn’t use the scientific method, it wasn’t a true investigation.”


Ms. Sneed opened a file on her laptop. “First, let’s take a look at Appendix F of the NGSS. It lists science and engineering practices. I’ve come to think of them as a scientist’s toolbox.”

After she turned her laptop toward him, Mr. Grow looked on.

“First,” the mentor said, “you can see that kids need to ask scientific questions. That means they need to understand what testable questions are. We’ll begin there. After that, we’ll explore:

Mr. Grow Learns How to Ask Testable Questions

She stood up and moved to the end of the table. “Let’s take a look at a fun back-to-school science investigation.” She motioned toward the materials gathered there.

“Sometimes show is better than tell. Today, I’ll show you how to ask scientific questions. Then tomorrow, you’ll present the same lesson to our class.”

Ms. Sneed picked up a bag of gummy bears and grinned. “Whenever we use stuff like this, kids go wild.”

Then she became more serious. “A testable question,” she said, “allows kids to compare, predict, observe, and in the best cases, measure.”

Kids in fourth and fifth grades need to understand elements of a testable question. In this experiment, they will ask a scientific question about gummy bears, water, and vinegar.
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To Ask Testable Questions, Kids Compare One Variable

Ms. Sneed set the gummy bears back on the table. Then she continued. “An old teaching friend of mine always began the year with a gummy bear experiment. Kids placed the candies in water and watched them expand. Sure, it was observable. And kids could make a prediction. But it lacked one important criterion: comparison.”

Now the teacher placed her hand on the vinegar. “As you may already know, testable questions change one thing. In this experiment, the only variable will be the liquid. Instead of just placing a gummy bear in water, they’ll also try vinegar.”

“Ah, the independent variable,” said Mr. Grow. “This process is definitely related to the scientific method.”

Ms. Sneed nodded. “Yep. Here’s more: Everything else is controlled. Same type of cup, temperature, amount of liquid, and time. Obviously,” she said with a smile, “we will drive the idea of sameness into their heads.”

Anyway, kids must ask scientific questions that include one independent variable. In other words, they must compare.”

A testable question compares two things. In other words, it has one independent variable. Here, two red gummy bears have been placed in equal amounts of water and vinegar.

Now Ms. Sneed poured 50 milliliters of vinegar into one cup and 50 milliliters of water into the second. “Measurement is such an important part of an experiment. In this case, I’m measuring volume to ensure that this variable is controlled.

“As you model testable questions for the students, reteach the concept of metric volume too. Review liters and milliliters. Constant reinforcement helps them master it.”

Next, she set a red gummy bear near the cups.

“I notice that they’re both the same color,” Mr. Grow said. “And the same size. And the same brand. More controlled variables.”

Ms. Sneed gave him a sidelong glance and chuckled. “Obviously, you’re prepared to teach kids to ask scientific questions,” she said.

Kids Should Be Able to Make a Prediction

“When elementary students ask scientific questions,” she continued, “they must be able to predict the outcome. In other words, kids should either have background knowledge or research that give them some idea of the phenomenon.”

As she spoke she slid a lab sheet down to Mr. Grow. “In my opinion, this is more about the teacher than the children. If we want them to hypothesize, we need to provide some context.”

“Do you have a preferred way for them to respond?” he asked.

“Thanks for asking! Yes, I like them to use question stems, just like we do with literary responses. Then I just ask them to tell what they think will happen.

“Let’s also spend a moment talking about incorrect hypotheses. Well, there’s no such thing! Let the kids know that proving their prediction wrong is just as good as proving it right. Every year, I have students who erase their hypotheses and rewrite them to match their results. No! We need to do everything in our power to keep this from happening.”

Mr. Grow nodded and made some notes in his plan book.

When kids ask scientific questions, they must also predict what will happen, or hypothesize.

Testable Questions Are Observable

“So,” said Ms. Sneed, “we’ve already discussed how testable questions must compare. Additionally, we talked about kids being able to predict.”

Without warning, Ms. Sneed plopped a red gummy bear in each cup. “Now we’ll discuss the third thing on my list. When kids ask a scientific question, they should be able to observe something. Take a look.” She waved her hand toward the cups.

“Aha,” Mr. Grow responded. “The gummy bear in water is bubbling. And is it my imagination? Maybe it’s expanding.”

Ms. Sneed nodded.

For a testable question, you must be able to observe something. Here, for example, you can observe two gummy bears in two different liquids (cause) and how one is bubbling and expanding (effect),

Measurable Questions Are Even Better

Next, she picked up the ruler. “Right. Kids can observe the gummies growing. But they’ll also measure the result, or dependent variable.”

For a moment, Ms. Sneed paused. Then she sighed. “In my opinion, fourth graders are old enough to understand the difference between qualitative and quantitative evidence. Sure, they could just eyeball the two gummy bears and then state which one was bigger. To me, however, quantitative data provides much more solid evidence. Measuring gives more solid proof.”

Then she slid the ruler under the clear plastic cup. “I wanted to show you how to measure the candy without a mess. As you can see, kids can read the ruler through the cup.”

“Brilliant,” her student teacher replied. “And don’t worry. I’ll review metric length, centimeters and millimeters as I teach this.”

Once again, Ms. Sneed chuckled. “Yep, you’re really getting the art of teaching. Good for you!”

When kids ask scientific questions, they should consider two types of measurement. First, measurement can ensure that variables are controlled. Second, it can provide quantitative evidence.

Students Practice Identifying Testable Questions

After shuffling through a stack of papers, Ms. Sneed slid a worksheet to Mr. Grow. “In addition to all of this, our kids will practice. This will help them ask scientific questions of their own.”

The student teacher looked a little confused. “Their own questions? I thought we were using the water and vinegar investigation.”

“Oh, we are. But that’s just for modeling. Afterward, kids get to ask scientific questions of their own – and then test them.”

“About gummy bears?”

“Yep. Fun, huh?”

Mr. Grow nodded enthusiastically. Then he picked up the worksheet. “So what about this?”

“In the past, I’ve used it in two ways. Sometimes I discuss testable questions, have them do the worksheet, and then launch into modeling with the water and vinegar experiment. Other times, I model the gummy bears in water and vinegar and have them do this worksheet afterward. The choice is up to you.”

When teaching kids to ask scientific questions, give them some practice with testable questions.

Teach Kids to Ask Testable Questions with These Labs

Mr. Grow sat back in his chair. Slowly, a smile spread across his face. “With labs like this,” he said, “I know I’ll enjoy teaching. Who knew that teaching kids to ask scientific questions could be so much fun!”

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