testable questions and hypotheses in controlled experiments

Testable Questions and Hypotheses in Controlled ExperimentsPre-AP Biology

• Scientists have long wondered whether life exists beyond Earth. One of the planets we have focused our attention on is Mars. When scientists conduct any research whether it be on distant planets or on planet Earth, they ask testable questions. Explain what a testable question means to you.

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Objectives• Demonstrate appropriate observational skills• Compose testable questions• Assess how each question could be tested• Define hypothesis • List characteristics a hypothesis should include• Write well-developed hypotheses to testable

questions

Importance• There are many questions in life but not all can be

tested and not all can be tested within a controlled experiment or environment.

• The goal of a scientist is to develop questions that are testable and from which a hypothesis can be developed.

Key Terminology• Hypothesis• Scientific Theory

Developing Testable Questions

• When developing questions ask yourself does T.E.R.M. apply? Does it involve an experimental treatment (T), is it ethical (E), is it replicable (R), and is it measurable (M).

Alka Seltzer Observation

1. Get into groups of 2-3.2. Get a alka seltzer tablet and place

in a small beaker of water. 3. Write down what you observe

happens with the alka seltzer tablet.

Alka Seltzer Observation

4. Relate you observation with the alka seltzer tablet to something you observed previously (your prior knowledge) by completing the following sentence

The dissolving alka seltzer tablet is like__________ because _______.

Development of Testable Question• Based on your observation, develop 3

testable questions about alka seltzer that you could answer by conducting an experiment .

• Be ready to share

Each group will

•Select one question that was testable, and design a way to test the question by identifying the experimental group, the control group, fixed variables, independent variable, and dependent variable

•Be ready to share.

Is your question testable?

Remember T.E.R.M.

Conduct T.E.R.M. Checklist Self Assessment to determine if you have all of the components of a testable question.

Definition of Hypothesis

• Tentative answer to the biological question that can be tested by experimentation

A good hypothesis should contain• Experimental Treatment• Predicted Result• Rationale – Explain why you expect the

result

Hypothesis should be in the form of• If …. then ….because………..

• First blank = experimental group• Second blank= predicted result• Third blank = rationale

Example of a Good Hypothesis• If the amount of fertilizer is increased then the seeds will

grow faster because they have more nutrients to use.• Circle the key components-• experimental group• Predicted result• Rationale

With your Group• Write 3 hypotheses based on the testable questions you

created on alka-seltzer observations.• Underline, circle or make a box around the three components

of a hypothesis for each hypothesis you wrote• Be ready to share

Think-Pair-ShareThink-Pair-ShareWrite down on your note-taker what you

think the difference is between a hypothesis and a scientific theory.

Share with a partner.

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Definition of Scientific Theory• Explanation for something that has occurred in nature that

has been tested by many different experiments and many different experimenters.

• This is different from a hypothesis that has been tested by only one experiment

Is the explanation of evolution by natural selection a Is the explanation of evolution by natural selection a scientific theory or a hypothesis?scientific theory or a hypothesis?

Thumbs up- scientific theory / Thumbs down-hypothesis

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Characteristics of Scientific Theory• Best possible explanation to a certain question based on

experiments and data collected• Not the absolute truth• Tentative – theory can be altered, revised or completely

abandoned as new data becomes available • Example of Theory: Dinosaur extinction is a result of a huge

asteroid that struck the Earth 65 million years ago.

Think-Pair-ShareThink-Pair-ShareWhy is the theory on dinosaur

extinction not set in stone? Write your answer on your notetaker.

Share with a partner

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Exit

Tic

ket

Pick 2 products you wrote down.

PROPERTY OF PIMA COUNTY JTED, 2010

On a 1/2 sheet of paper

Keeping the experiment that your group

designed in mind, list some reasons why the question you chose was testable and could generate a hypothesis

Turn your responses in.