Assessment-Bias and Error (Other Teachers)

Name: ID:

Email:

Instructions
1) Type in your first and last name in the “Name” box in the top-left corner.
2) Next type in your teacher’s name in the “ID” box.
3) Then type in your school’s name in the “Email” box.
4) Select the best answer for each question.
5) When you are finished click the “Grade and Submit” button.
6) The grade will be emailed to your teacher.

Alex wants to determine if the weight of a model rocket affects how high the rocket can shoot up into the air. To do this, he constructs four different types of rockets and then fills three of the rockets with varying amounts of sand to add weight. He does not put any sand in the 4th rocket. He then launches these rockets straight up one at a time and records how high they travel.
---The independent/manipulated variable is the amount of weight (sand) per rocket.
---The dependent/responding variable is the height that they reach.
---The control trial is the rocket launched without any extra weight (sand) in it.

Identify a key error in this experiment

a.	He should have used more weight for each rocket. They should have been heavier.
b.	He should have used helium filled balloons instead of rockets for this kind of experiment.
c.	Each rocket should have been identical, but instead he used four different types of rockets.
d.	Each rocket should have included a parachute to allow it to gently float down to the ground.

Some students investigated plant growth by growing two sets of the same type of plant. One set was grown indoors and the other set was grown outdoors. They recorded data in the table below.

The students concluded that the plants grown indoors grew faster because they received better quality light than the plants grown outdoors.
Which is the most likely reason this conclusion may be flawed?

a.	The growth of the plants in each set was affected by more than one factor.
b.	The students measured the plants at different times.
c.	The outdoor plants grew faster than the indoor plants.
d.	The students should have grown different types of plants.

The owner of “Super Grow” garden soil company wants to sell his brand of soil to gardeners that grow flowers. His “Super Grow” soil contains a mixture of top soil, mulch, peat, and fertilizer. He hires a scientist to conduct an experiment to demonstrate that his brand of garden soil is superior to other brands by measuring the amount of growth in flowers over a 30 day period. The results are shown below.

Brand of Garden Soil	Roses Average Growth	Tulips Average Growth	Carnations Average Growth
“Super Grow”	18 cm	11.9 cm	16 cm
“Amazing Plants”	18.2 cm	12 cm	16.3 cm
“Green Tree:	16 cm	10 cm

After the experiment, the owner of “Super Grow” advertises his soil as being better than the other two brands. Select the answer below that best describes his bias.

a.	His claim does not match the experimental data. “Amazing Plants” was slightly better.
b.	His claim is accurate based on the results of the experiment.
c.	He is biased because the experiment used too many types of soil
d.	His advertising is false because the experiment should have lasted 60 days.

A calcium supplement designed to make bones stronger was given to two groups of people during a scientific study as displayed in the table below

	Dosage
Group 1	30 mg each day
Group 2	60 mg each day

After 60 days, all the people had their bone density tested and the results appeared to show that their bones were marginally stronger. However they neglected a key task when they did their experiments. Identify the key task that they did not do.

a.	Give the supplement to both groups for only 30 days
b.	Create a third group (a control group) that does not receive the supplement
c.	Create a third group that receives 75mg of the supplement
d.	Test only one group with 100mg of the supplement

A student investigated how much water different soil types can hold. The students placed each soil sample in a container with small holes in the bottom. The student poured water into the container of soil, and then recovered the water that drained from the soil. Data from this investigation are shown in the table below.

After reviewing the data, the student concluded that sand could not hold as much water as clay or loam. Which is the most likely reason this is an invalid conclusion.

a.	The student should have tested more than three types of soil.
b.	The student should have recovered the same amount of water from each type of soil.
c.	The student should have poured different types of liquid over the soils.
d.	The student should have poured the same amount of water over each soil.

Jeanette was conducting an experiment to determine if plants grow better when exposed to rap music. She bought two identical plants and exposed one to rap music for two weeks while the other grew without music. From the data, Jeanette determined that plants do not grow better with rap music.
Which of these would explain why Jeanette’s conclusion may NOT be valid?

a.	The experiment could never be repeated.
b.	She never formulated a question.
c.	There was no control group.
d.	She should have tested more than two plants.

A student conducted an experiment to determine which sponge shape would absorb the most water (see table above). The independent variable was the shape of the sponges. The amount of water each sponge absorbed was the dependent variable. After finishing the experiment, the student thought that the most absorbent sponge was the irregular shaped one. However later he realized that he had left out one critical piece of information in the table.
What key information did he leave out?

a.	The color and odor of the sponges both before and after they were wet.
b.	The mass and volume of the sponges before they were wet.
c.	The length of time that it took him to complete the experiment.
d.	The names of the stores where each sponge was purchased.

A vitamin supplement designed to prevent the common cold was given to two groups of people during a scientific study.

Groups	Dosage
Group 01	50 mg/day
Group 02	100 mg/day

After eight weeks, neither group reported a case of the common cold.
Which of the following would have made the outcome of this study more valid?

a.	Give the supplement to both groups for only 6 weeks.
b.	Create a third group that does not receive the supplement
c.	Create a third group that receives 75 mg of the supplement.
d.	Test only one group with 150 mg of the supplement.

Students hypothesized that drinking a can of Red Bull energy drink would enable them to run faster. So four students each consumed one 12oz (355mL) can of Red Bull, and then they each were timed running a distance of one kilometer. Their results are shown below.

Student	Run Time (1 kilometer)
1	7 minutes
2	8.5 minutes
3	6.75 minutes
4	10 minutes

Based on the data above, a valid conclusion cannot be made because...?

a.	Control data of normal run times without the energy drinks was not collected
b.	Not enough trials were conducted to be able to draw a conclusion
c.	The variability in run times among the students is too great.
d.	The run distance was too short to make a valid determination

10.

Joanna and Stephanie have been doing research about global warming. They noticed that several types of organisms, such as armadillos, gnats, and alligators, are now found much farther north than they were found twenty years ago. They conclude that the change of location for these species is directly related to global warming.
What would you tell them about the validity of their conclusion?

a.	They should research more species to see if others have moved farther north over the last twenty years.
b.	Global warming could not cause a species to move to different locations.
c.	They should test their hypothesis before coming to that conclusion.
d.	They have made a valid conclusion.