Experimental Design

The analysis of data gathered during a particular experiment is necessary in order to

• formulate a hypothesis for that experiment

• develop a research plan for the experiment

• design a control for the experiment

• draw a valid conclusion for that experiment

Tags

NGSS.HS-PS1-3

A student conducted an original, well-designed experiment, carefully following proper scientific procedure. In order for the conclusions to become generally accepted, the experiment must

• contain several experimental variables

• be repeated to verify the reliability of the data

• support the original hypothesis

• be conducted by a scientist

Which statement best describes a hypothesis

• A hypothesis is the process of making careful observations.

• The conclusion drawn from the results of an experiment is part of a hypothesis. The conclusion drawn from the results of an experiment is part of a hypothesis.

• A hypothesis serves as a basis for determining what data to collect when designing an experiment. A hypothesis serves as a basis for determining what data to collect when designing an experiment.

• The facts collected from an experiment are written in the form of a hypothesis. The facts collected from an experiment are written in the form of a hypothesis.

Tags

NGSS.HS-PS1-2

Conclusions based on an experiment are most likely to be accepted when

• they are consistent with experimental data and observations

• they are derived from investigations having many experimental variables they are derived from investigations having many experimental variables

• scientists agree that only one hypothesis has been tested

• hypotheses are based on one experimental design hypotheses are based on one experimental design

Tags

NGSS.HS-PS1-3

A student is opening and closing clothespins as part of a lab activity. The student begins to experience muscle fatigue, and the rate at which the student is opening and closing the clothespins slows. Which graph best represents the relationship between time and number of clothespin squeezes?

• 1

• 2

• 3

• 4

Students wanted to try PRE to increase their ability to rapidly squeeze a clothespin. They thought if they could do this, they could challenge another class to a clothespin squeezing competition and win. Which steps should the students take to follow the principles of PRE?

• Measure their pulse rate after squeezing the clothespin until fatigued. Then increase the resistance of the clothespin for the next trial.

• Squeeze a clothespin until fatigued, rest, and repeat. Over time, they should gradually increase the resistance of the clothespins they are squeezing.

• Measure their pulse rate, squeeze a clothespin for one minute, rest, and measure their pulse rate.

• Squeeze a clothespin for as long as they can, measure their pulse rate, rest, eat some candy. Increase the resistance of the clothespin for the next trial.

Which statement is best supported by the data in the chart?

• After exercise, the nonathletic students had a lower heart rate than the athletic students.

• After exercise, the heart rates of the athletic students returned to resting pulse in four minutes.

• During exercise, both groups of students had the same increase above their resting pulse.

• During exercise, the athletic students had a higher heart rate than the nonathletic students.

Tags

NGSS.MS-PS3-1

To improve the validity of the conclusion reached in this experiment, the students should repeat the experiment

• disregarding any data that don’t fit the hypothesis

• with a larger number of athletes and nonathletes

• comparing the heart rates and breathing rates of males and females

• with the athletes doing different exercises than the nonathletes

Tags

NGSS.HS-ETS1-2

In an experiment to determine the effect of exercise on pulse rate, a student checks his pulse rate before and after exercising for several minutes. The purpose of checking his pulse rate before exercising is that it

• is needed to formulate a hypothesis

• is needed to justify the sample size

• serves as a control for the experiment

• serves as the conclusion for the experiment

Tags

NGSS.MS-ETS1-1

Which statement about the use of independent variables in controlled experiments is correct?

• A different independent variable must be used each time an experiment is repeated. A different independent variable must be used each time an experiment is repeated.

• The independent variable must involve time.

• Only one independent variable is used for each experiment

• The independent variable state the problem being tested.