Learning Objective:We will learn how to design an

experiment using a research plan for a given scientific

problem.

Catalyst:Have you ever conducted your own “experiment” at

home? What were you trying to “test”?

Formulate a hypothesis for a given scientific problem.

Design an experiment for testing a hypothesis by determining independent, dependent, and control variables, and list steps to follow in order to conduct the experiment.

Learning Objective:We will learn how to design an experiment using a

research plan for a given scientific problem.

A good hypothesis tries to explain what has been observed in a way that can be tested.

Most of the time, hypotheses are stated in an “If...then...” statement.

Experiments cannot PROVE a hypothesis; they either support the hypothesis or fail to support it.

Learning Objective:We will learn how to design an experiment using a

research plan for a given scientific problem.

Directions: What do you think causes plants to grow? Create a hypothesis!

Start with: “If you ________, then the plants will grow taller”

Learning Objective:We will learn how to design an experiment using a

research plan for a given scientific problem.

Hypothesis:

If you add fertilizer to plants, then the plants will grow taller.

Learning Objective:We will learn how to design an experiment using a research

plan for a given scientific problem.

The experimental groups are the groups getting tested.

You cannot have only one experimental group!

In our experiment, what would the experimental groups have?They would be applied with fertilizer (and different amounts of it in each).

Learning Objective:We will learn how to design an experiment using a research

plan for a given scientific problem.

A control is the group that is “normal.” You compare your results from the

experimental groups to the control group.

In our experiment, what would be the control group?Plants that do not have any fertilizer.

Learning Objective:We will learn how to design an experiment using a research

plan for a given scientific problem.

The dependent variable is what you are measuring in the experiment.

It is easier if you think about it like this:“The effect of ______ on ______”

In our experiment, what would be the dependent variable?

“The effect of fertilizer on plant growth.”

Learning Objective:We will learn how to design an experiment using a research

plan for a given scientific problem.

Independent variables are factors that influence or affect the dependent variable.

These are variables that you want to keep the same between the control group and each of the experimental groups.

Learning Objective:We will learn how to design an experiment using a research

plan for a given scientific problem.

It is easier if you think about it like this:“The amount of _______”

In our experiment, what would be (some of the) independent variable(s)? The amount of sunlight/water/soil/etc.

Learning Objective:We will learn how to design an experiment using a research

plan for a given scientific problem.

Question Answer

What is your hypothesis?

The hypothesis should suggest a possible answer to the question you are investigating.

What is your dependent variable?

What should change and/or be measured as a result of the experiment? Make a data table to record the data as they are collected.

What is your independent variable?

What is the treatment? Are you only changing one factor at a time to see its effect? Will there be several groups with more than one treatment?

Describe how you will control the experiment.

What other possible factors may vary that could also affect the results and make your experiment inconclusive (not good)?

What steps will you take to conduct this experiment?

Make a list of procedures and materials needed to conduct the experiment.

Learning Objective:We will learn how to design an experiment using a research

plan for a given scientific problem.

A pharmaceutical company is testing a new drug that cures cancer. They conduct an experiment (following all the necessary protocol that we have discussed) and they find that out of 100 cancer patients tested, 71 patients were cancer-free, 26 experienced no effect, and 3 patients died. What would you do if you were the lead researcher in this experiment?

Learning Objective:We will learn how to design an experiment using a research

plan for a given scientific problem.