Experimental Investigations

Science - Investigations vs. Experiments

​SC.5. N.1.2 Explain the difference between an experiment and other types of scientific investigation.

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​SC.5.N.1.4 Identify a control group and explain its importance in an experiment

Multiple Choice

A student finds a video that shows a bottle of soda fizzing up and gushing out when Mentos candies are dropped into the soda. The video claims that this “experiment” show a chemical reaction. Which of the following is the BEST reason that this is NOT an experiment?

• It was only tried one time. There was no hypothesis, no control, and no variable.

• It was only tried one time. There was no observation or data collection.

• It was only tried one time. There was no prediction.

• It was only tried one time. There was no conclusion.

What do you notice? All experiments are investigations. Not all investigations are experiments. There are two things that have to be present in the plan for an investigation for it to be an experiment. The first is a testable question called a hypothesis. “If the amount of water is doubled, then the rate of growth of a plant will increase” is an example of a testable question. How that question is tested is the second thing that is needed to make an investigation an experiment: a control group and a variable.​

​Observe experiments and other types of investigations.

Multiple Choice

What are the things that needed to be present in the plan for an investigation for it to be an experiment?

• hypothesis and observations

• observations and control groups

• testable question, a control group and a variable

• a control group and a hypothesis

Multiple Choice

TRUE or FALSE

ALL investigations are experiments, but not all experiments are investigations.

• TRUE

• FALSE

​In this example, twelve plants will be grown so that there is a sufficient number of repeated trials. Six of the plants will be placed into group A, and six into group B. Group A will receive 4 ml water for ten days.

Group B will receive double the amount of water for the same ten days.

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​All twelve plants will be planted in the same pots, with the same mix, and placed on the same table in the classroom.

Group A is the control group: it is going to receive the “regular” amount of water.

​Nothing is being changed about group A. Group B is testing the variable. Group B is set up identically to group A, except that the amount of water will be changed, or varied. Group B is testing the variable: the amount of water has been doubled for this group.

Multiple Choice

Group A is the control group;  it will receive the __________ amount of water

• regular

• complete

• doubled

• tripled

Multiple Choice

All experiments are investigations. Experiments have a hypothesis, a control, and a variable. Which if the following BEST shows a variable that could be tested using soda and Mentos?

• changing the kind of soda used

• recording the amount of soda left in the bottle after the investigation

• observing the amount of soda on the ground after the investigation

• moving the investigation to another location

​At the end of this investigation, systematic empirical data will provide evidence to conclude whether more water is the best condition for plants to grow. This investigation tested a question. The investigation’s group A was a control group. Group B tested a variable: the amount of water. By comparing Group B’s growth to group A’s, this experiment will answer the tested quested with empirical data.

Multiple Choice

At the end of this investigation, systematic ______________ data will provide evidence to conclude whether more water is the best conditions for plants to grow.

• observational

• empirical 

• control group

• investigational