How do you teach students to write a good scientific hypothesis? Many teachers use “If, then” statements to teach this important science skill. But, at the end of the day, do they really know how to write or identify a good scientific hypothesis? According to results from a recent REAL Science Challenge contest, many students don’t. Roughly x% of participants struggle to identify the hypothesis to an experiment. When put in context, it’s x students in a class of 30 who struggle with hypothesis writing. So, even after going over how to write a scientific hypothesis, students still struggle with identifying them. Is this because there is still confusion regarding what a hypothesis is? Or, is it because students don’t know how to apply their knowledge in a different context? In other words, what we need is for students to understand what a hypothesis is and to apply it to different contexts. But, how do we do this in a meaningful and simple way?

First, we need to look at the structure or a hypothesis and boil it down to its component parts, A scientific hypothesis simply consists of 2 parts. Therefore, if we use a 2-step template to help students write a scientific hypothesis, students may find this more helpful. We go through our 2-step hypothesis and applicable examples below. Handouts are available at the end of the post.

What is a scientific hypothesis?

Basically, a scientific hypothesis is a testable explanation for a scientific phenomena or question. Let’s break that down.

First, a scientific hypothesis is a scientific explanation. A statement that makes clear the causes or reasons for a scientific phenomena or question. For example, we could ask, “how do musicians sell more records?”  And, our hypothesis could be “Record sales depend on the amount of impressions or views the record receives online.” So, is this a good scientific hypothesis? It’s close, but it’s still incomplete.

Besides being an explanation, a scientific hypothesis must also be testable. In other words, scientists can observe or measure changes when they adjust or manipulate parts of the hypothesis in an experiment. The testable part of a scientific hypothesis typically comes in the form of an “if, then” statement. For example, to make the above hypothesis about musical record sales more complete, we can add the following: “If the number of Youtube views for a record increases, then the number of sales for the record will increase.”

The 2-step approach to hypothesis writing

Perhaps a straightforward way to teach hypothesis writing is to take a 2-step approach and to make a hypothesis at least 2 sentences long.

Note: there is no accepted length requirement to a hypothesis, although many students may get the wrong impression that a hypothesis is supposed to be 1 sentence in length.

Also note: before students begin to write a hypothesis, they must start with a question, which either they receive or come up with. If a phenomenon or experimental evidence is given instead, then this can be turned into a question by asking “why does that happen? Or “how does <the phenomenon> work?”. With question in hand, students can start the 2-step hypothesis writing process.

How to do a 2-step hypothesis

STEP 1: Come up with a specific reason or reasons that explain the phenomena or question. Consider using the following template to start your hypothesis:

The <phenomenon, topic> (is due to, is caused by, depends on) <specific reason>

Make sure students provide specific details. For example, saying “Record sales depend on an artist’s popularity” isn’t specific enough.

To make a stronger statement, define what type of popularity. For example, “Record sales depend on an artist’s popularity – specifically, the number of online followers the artist has before the release of the album”. This is a much stronger statement as it defines what type of popularity (ie. Online, social media) and when (ie. Before the release of an album).

STEP 2: Write a testable statement. In other words, provide a way in which the hypothesis can be tested.. Consider using an “If, then” statement and structure the statement like this:

“If <independent/manipulated> variable <increases/decreases>, then <dependent/respondent> variable <increases/decreases>”

Remember, a independent or manipulated variable is something a scientist or researcher has the power to directly change. The dependent or respondent variable is the something that responds to the changes of the independent variable. In the case for our hypothesis above, online followers is the independent variable and record sales is the dependent variable.

Therefore, we can write the testable statement “If the number of online followers an artist has increases, then the artist’s record sales increases.” This is a fairly straightforward statement that is easily testable. That is, track an artist’s online followers and see if it correlates with an increase in record sales.

Aside: There is no one “right” hypothesis

Lastly, there can be many hypotheses that explain the same phenomena. Students do not need to feel as though they need to get the “right one”. For example, for our question, “How do musicians sell more records?”, there can be multiple hypotheses – all of which can be credible:

“Record sales depend on the amount of radio play the record receives. If the radio play for a record increases, then the number of sales for that record increases.”

“Record sales depend an artist’s activity on social media platforms. If the number of Facebook Live, SnapChat, and Reddit AMA events hosted by the artist increases, then the artist’s record sales increase.”

“Record sales depend on early reviews by ‘influencers’. If number of early reviews by influencers increases, then the artist’s record sales increase.”

Wrap Up

Part of teaching science is teaching scientific literacy. Experimental design, identifying variables, hypothesis writing – are all part of that scientific literacy. To help students grasp science literacy quicker, it’s important to provide templates and standard customs, both of which teachers may already know bit take for granted. Click the link below to download our handouts. Thanks for your interest! Also, if you find this resource helpful, please share this with your colleagues.

Until next time, keep it REAL!

Resources

Handout(s): 35 – 2 Step Hypothesis Writing

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