RT: design an experiment
1. A scientist wants to explain why a phenomenon occurs the way it does. Rank the following processes from first to last in a scientific
experiment that might help provide the answer:
1. Draw a conclusion about the explanation
2. Make a prediction
3. Conduct an experiment
4. Generate an explanation
A) 2, 3, 1, 4
B) 1, 3, 4, 2
C) 4, 2, 3, 1
D) 3, 4, 2, 1
WBT: draw conclusions from evidence
2.
A chemistry student heats a beaker of ice water while observing the temperature continuously with a thermometer. While constantly
stirring the ice water mixture, and after applying the heat for a while, the temperature of the ice water mixture does not rise. She concludes
that heat does not raise the temperature of water so long as it is constantly stirred. What would be necessary to justify this conclusion?
A) Nothing; it is an acceptable conclusion as stated.
B) This would be a correct conclusion only if there were no ice present during the process.
C) This would be correctly only if the experiment started with ice only.
D) This would be true only if there was no stirring.
WWT1: Fails to control an important variable during an experiment
3. An agricultural researcher wants to see how effective one fertilizer is compared to another. The researcher plants soybeans in two plots
located 3 miles apart. Plot #1 is an open field where brand X fertilizer is applied; plot #2 is surrounded by a forest where brand Y fertilizer is
applied. What, if anything, is the biggest problem with this experiment’s design?
A) Nothing; the experimental design is suitable for testing the fertilizers.
B) The design fails to control for important variables that might affect the outcome of the experiment.
C) There is a lack of a suitable control plot where no fertilizer is applied.
D) There might be contamination of one fertilizer with another.
Improve experimental design
4. How best might the design of the experiment dealing with brand X and Y fertilizers be improved, if at all?
A) The experiment need not be improved.
B) Select plots closer together than 3 miles.
C) Apply brands X and Y to separate halves of both plot #1 and plot #2.
D) During year 2, use brand Y on plot 1 and brand X on plot #2 and then average the results.
WWT2: Fails to provide for a control group during an experiment.
5. A medical research scientist wishes to test the effectiveness of a drug on a certain disease. She seeks patients with the disease and obtains
25 volunteers. The drug is properly administered to the volunteers, and two weeks later the disease disappears. What, if anything, is wrong
with this experimental design?
A) Nothing; the experiment was properly done and the drug was proven to be effective.
B) This sort of drug trial should never use volunteers; its biases the outcome.
C) The scientist did not wait long enough to see if the disease would come back.
D) There was no control group.
BCT: interpret data
6. A physics student uses a spring scale to measure the weights of a number of
masses each with the amount of mass stamped by the manufacturer into the
base. After graphing the data and finding the best-fit line, the student declares,
“When the mass of a weight is zero, it will have a weight of 1 newton.” Do you
agree, and why or why not?
A) Yes, because the data predict this phenomenon.
B) Yes, the student has discovered something new.
C) No, making predictions beyond the range of data is wrong.
D) No, this situation would be physically impossible.
Deal with unexpected results
7. In the above investigation, what is the most likely reason for the slight scatter in the graphed data?
A) The spring scale used was slightly inaccurate.
B) The scale was not adjusted to read 0 when no weight was hung on it.
C) The scale has a spring that has been over stretched.
D) The labels on the masses are clearly wrong.
CRT: interpret and analyze data
8. In the above investigation, what is the most likely reason for the best-fit line not going through the origin (0, 0) of the graph?
A) The spring scale used was slightly inaccurate.
B) The scale was not adjusted to read 0 when no weight was hung on it.
C) The scale has a spring that has been over stretched.
D) The labels on the masses are clearly wrong.
Design an experiment.
9. A scientist wishes to find the relationship between variables X and Y in a system with many variables (such as R, S, and T). How would
the experiment best be conducted?
A) Don’t conduct an experiment, just compare means, medians, and modes of X and Y.
B) Vary X and observe any changes in Y while holding all other variables like R, S, and T constant.
C) Hold X constant while varying Y and observing other variables like R, S, and T.
D) Vary both X and Y, and see how these changes affect other variables like R, S, and T.
Interpreting data
10. Here is a graph of a toy car’s motion, showing position with the passage
of time. Which of the following sentences correctly describes the car’s motion?
A) The car doesn’t move at first. Then it moves backward at a constant speed
and finally stops.
B) The car moves along a flat surface. Then it rolls forward down a hill, and
finally stops.
C) The car is moving at constant speed. Then it slows down and stops.
D) The car moves along a flat area, goes forward down a hill, and then keeps
moving.
Draw proper conclusion from a model
11. 1,000 rabbits are introduced to a certain area where the rabbits have no
natural predators. The graph to the left shows their population in this area by
year since the introduction of the rabbits. What can a scientist properly
conclude from the population data?
A) Predators entered the area around year 15.
B) There is widespread disease among the rabbits.
C) The rabbit birth rate nearly matched the death rate by year 30.
D) The rabbits are running out of food.
CC: Several competing “hypotheses” – which one is best?
12. An old flashlight fails to work and the user wants to fix it. In order to fix
it, the user comes up with an explanation for the failure in order to guide
testing. Which one of the following explanations would be best for guiding
testing?
A) The flashlight has dead batteries.
B) The flashlight is old.
C) The flashlight’s protective lens cover is missing.
D) The flashlight’s body is made of metal.
Drawing conclusions; interpreting data
13. A scientist explains that under identical experimental conditions, cornfield #1 produced 603 bushels of corn and that cornfield #2
produced 822 bushels of corn. The scientist states, “Nearly 60% of all corn produced came from field #1. Clearly, the fertilizer used in field
#1 is superior to that used in field #2.” What is the next logical step for farmers depending on this information?
A) Conduct the experiment a second time to see if they can replicate the 60% result.
B) Purchase large amounts of the fertilizer used on field #1.
C) Indicate that the experimental design is flawed.
D) Point out the error in the scientist’s statement.
Interpreting data
14. A “leading scientist” explains in a television commercial that in a study of
12 adults, dieters sometimes lost as much as 20% of their body weight when
they used the Zircon Diet. The accompanying chart is shown as evidence.
What can the viewer legitimately conclude about the Zircon Diet from this
chart?
A) The 20% loss results are not typical.
B) The diet is safe and effective.
C) If I use this diet, I will lose 20% of my body weight.
D) The diet is both dangerous and ineffective.
Eliminate inappropriate data:
15. A student is collecting data about how the voltage of a battery changes
over several weeks. The same equipment was used during the experiment, and
there are no changes in the set up. On week 17, the data are plotted on a graph.
A “blip” appears for week 9 when the voltage recorded is much higher than
expected. How could one best explain this “blip” in the data?
A) Something was wrong with the data collection process during week 9.
B) The voltage provided by the battery suddenly “surged” or “spiked.”
C) There was test equipment failure during week 9.
D) There was no “control” battery in this experiment.
Interpreting data
16. These data illustrate the effects of evaporative cooling of two alcohols,
Ethanol
Methanol
methanol and ethanol. A temperature probe is placed in each container of
alcohol, both at 22oC. The data collection begins, and about 25 seconds later
(to ensure equilibrium) the probes are removed from their containers. Methanol
and ethanol then evaporate from the temperature probes. What conclusion can
be derived from these data?
A) The methanol cooled the temperature probe to a lower temperature than the
other alcohol, and did so more rapidly.
B) The ethanol cooled the temperature probe to a lower temperature than the
other alcohol, and did so more rapidly.
C) The methanol cooled the temperature probe to a lower temperature than the
other alcohol, and did so less rapidly.
D) The ethanol cooled the temperature probe to a lower temperature than the
other alcohol, and did so less rapidly.
Interpreting data
17. This is a record of barometric (air) pressure recorded in Portland, Oregon,
during a big storm. The time scale on the graph shows hours after midnight
starting 12/12/95. About 18 hours later, around suppertime on 12/12/95, the storm
hit Portland. What can one properly conclude from these data?
A) Low air pressure causes big storms.
B) Low air pressure is associated with big storms.
C) Falling air pressure always follows the passage of big storms.
D) Falling air pressure always comes before big storms.
Understanding graphs
18. The speed of a freely falling object is recorded using a motion detector.
The speed and time data are recorded on a graph shown to the left. What does
the slope of the best-fit line represent?
A) The average speed
B) The speed of impact with the ground
C) The starting position at time = 0
D) The change of the speed with time (acceleration)
Understanding graphs
19. In this same speed vs. time graph, what does the y-intercept represent?
A) The speed of impact with the ground
B) The speed at time = 0.
C) The acceleration of the object.
D) The lowest point in the flight path.
Formulate and revise scientific explanations and models using logic and evidence.
20. Early astronomers thought that the planet Venus orbited a fixed point located on a line between the Earth and Sun. That is, Venus was
always located roughly between the Earth and Sun. When Galileo looked at Venus through his telescope in 1609, he saw that Venus
exhibited a complete set of phases – crescent, quarter, gibbous, and full. What can be concluded from the full set of phases?
A) The telescope was playing tricks on Galileo.
B) Bright reflections made Venus appear to go through a complete set of phases.
C) Venus actually orbits the Sun, and not some imaginary point between the Earth and Sun.
D) Nothing – a complete set of phases would be expected even if Venus were always between the Earth and Sun.
Recognize and analyze alternative explanations and models.
21. A student says that the Sun’s rising in the east and setting in the west is proof of the Earths’ rotation (spinning). Do you agree or
disagree with this student, and why?
A) Agree, because if the Earth were really spinning, we’d feel the motion
B) Agree, because if the Earth were really spinning, things thrown up in the air would be left behind.
C) Agree, because if the Earth were really spinning from west to east, there would be a constant wind from the east.
D) Disagree, the Earth could just as well be standing still with the Sun orbiting it once daily.
Communicate and defend a scientific argument.
22. A geologist looks carefully at a globe of the Earth and notes how the east coast of South America seems to fit almost perfectly into the
west coast of Africa. He further notes that the “bump” on the west side of Africa seems to fit nicely into the Gulf of Mexico to the south of
the United States. He then concludes that Africa and the Americas were connected millions of years ago. What sort of scientific evidence
would be required to support this claim?
A) The animals currently living in Africa would have to be the same as those in corresponding parts of the Americas
B) The rock formations and types of Africa would have to be the same as those in corresponding parts in America.
C) The plant life currently present in Africa would have to be the same as that in corresponding parts of the Americas.
D) All of the above must be true if we are to believe that Africa and the Americas were together millions of years ago.
Predict trends within data sets.
23. A physicist measures the force between to two objects as a function of distance. The time that observations were recorded, the separation
(in millimeters, mm), and the force (in specialized units, f ) are recorded as in the table. What meaningful trend is apparent from the data?
Time
Distance (mm)
Force (f )
A) As separation doubles, the force doubles.
B) As separation doubles, the force halves.
10:15 a.m.
8
0.0156
C) The distance is dependent upon time.
11:20 a.m.
5
0.0400
D) None of the above appropriately describes a meaningful trend to be found
1:05 p.m.
4
0.0625
in the data.
2:30 p.m.
2
0.2500
4:15 p.m.
1
1.0000
Recognize limits of investigation methods:
24. A student hypothesizes that the reason wood floats in water is because there are unobservable “water nymphs” that push up on the wood
from beneath. What is wrong, if anything, with this explanation from the perspective of a scientist?
A) There is nothing wrong with this explanation.
B) The water nymphs are too small to be seen.
C) The explanation is not testable.
D) The student needs counseling.
CC: Conduct a controlled experiment – how best to test a hypothesis; which do you agree with and why?
25. Objects weighed in air are heavier than when weighed in a liquid. For instance, a rock weighs more in the air and less in water. The
upward force exerted by the water that helps support the rock is known as the buoyant force. A group of students wants to see how mass (or
weight) influences buoyant force, and come up with the following list of materials to use in an experiment:
Object
cube
cylinder
sphere
disk
Mass (grams)
75
100
100
75
Weight (ounces)
2.64
3.52
3.52
2.64
Volume (cm3)
27.8
27.8
53.3
53.3
Material
Metal
Stone
Metal
Stone
Which two objects should students use in their initial test to see if mass (or weight) has a significant effect on the amount of buoyant force?
And why should this be so?
A) Cube and disk; because the masses need to be the same for a controlled experiment.
B) Disk and cylinder; because the materials need to be the same for a controlled experiment.
C) Cylinder and cube; because the volumes need to be the same for a controlled experiment.
D) Sphere and cylinder; because the weights need to be the same for a controlled experiment.
Random Sampling:
26. A biologist wants to sample the height of bamboo plants in a tropical rain forest. For ease of data collection, the biologist randomly
samples bamboo plants located around the edge of the rain forest. Is this an appropriate form of sampling? Why or why not?
A) Yes; as long as the sample is random this will give a good average for the forest as a whole.
B) Yes; the fact that travel is rain forests is difficult justifies the procedure.
C) No; because the sampling occurred only at the edge and not across the whole forest, the sample will be biased.
D) No; because to get the true average, every plant in the forest must be measured.
Valid and reliable:
27. The “targets” below show the scatter of data for an experiment repeated four times. The expected result of the experiment is that all data
should hit the center of the target. Based on this assumption, which data set represents data that are comparatively repeatable but inaccurate?
A)
B)
C)
D)
Review literature for validity:
28. A researcher uses a web page furnished by the nuclear power industry to find out what the arguments are against the construction of a
nuclear power plant. Is this a valid way to determine the nature, type, and number of such arguments? Why or why not?
A) Yes, the nuclear power industry is regulated by the US government to ensure fair and honest dealings with the public.
B) Yes, there are “watchdog” agencies and “bloggers” that ensure that both sides are always telling the truth.
C) No, the nuclear power industry might be biased against opposition groups and might not accurately represent opposition arguments.
D) No, the nuclear power industry will be quite unaware of the number, types, and nature of arguments arrayed against them.
Generate inquiry questions:
29. A science teacher drops a red cylinder through a long vertical tube made of a non-magnetic metal (aluminum or copper), and it hits the
ground almost immediately. The science teacher then drops what appears in size and shape to be identical blue cylinder through the same
vertical tube, and it drops out the other end only after five seconds. The students are awe struck, and want to know why this happened. The
teacher demonstrates the phenomenon several more times with the same results. Which of the following would be the best question to ask to
start a scientific investigation of the phenomenon?
A) How do the red and blue cylinders differ?
B) What effect does color have on the speed of fall?
C) What are the weights of the red and blue cylinders?
D) What is the nature of the force that influences blue cylinders but not red cylinders?
QRT: Given initial and final conditions, ask to develop a hypothetical explanation.
30. What is the most likely explanation of the above demonstration with the red and blue cylinders?
A) The tube has somehow become clogged with an obstruction.
B) The science teacher is playing a magic trick on the students.
C) The slower moving cylinder is really larger than it appears and gets stuck in the tube repeatedly.
D) There was a resistive force operating between the tube and the slower blue cylinder.
Compare qualitative/quantitative or subjective/objective data:
31. Two blocks, one of metal and the other of wood, have been sitting in a room all day long. The room has a constant air temperature of 72
degrees Fahrenheit. When a person picks up the metal, it feels cool to the touch; when the wood is picked up, it feels comparatively warm.
Which of the following conclusion may the person properly make, and why?
A) The metal is cooler than the room; personal impressions are to be trusted over numerical data.
B) The metal is at the same temperature as the wood; numerical data are to be trusted over personal impressions.
C) The wood is warmer than the room; personal impressions are to be trusted over numerical data.
D) The wood is at the same temperature as the room, but seems warmer because it is not as hard as metal.
Determine appropriate research components.
32. A student wants to determine accurately how far a meter stick will fall past the 50-cm starting point when released from rest between his
thumb and index finger. Someone else releases the meter stick and it is caught by the time it has moved to the 73-cm mark. The release is
repeated four more times with the following capture points: 68 cm, 81 cm, 75 cm, and 78 cm. The average capture point is calculated to be 75
cm. The reaction time is calculated with use of a formula to be 0.22 seconds. What is the most probable reason the student conducted
multiple measurements rather than just one?
A) The human reaction time is not zero, as this experiment clearly shows.
B) The student was uncertain that the distance was measured properly each time.
C) The student might have “anticipated” the release and closed his fingers early or otherwise failed to react as quickly as possible at some
times but not at others.
D) There is always an error in reading a stopwatch because the human reaction time is on the order of 0.2 seconds.
Appropriate survey or interview methodologies.
33. High school students want to determine how the members of their large rural county really feel about the installation of a wind farm on
the outskirts of the town where their high school is located. Which would be the best way to generate a reliable answer to this question?
A) Stop adults in the local shopping mall and ask them to complete a survey.
B) Send out a randomly distributed survey to 10% of the people living all around the county.
C) Go door to door to every house in town to ask people what they think about the wind farm.
D) Ask experts, scientists, and other individuals associated with the wind farm project what they think.
Reflect on procedural refinements
34. A scientist wants to measure the thickness of a single sheet of paper. All he has is a 30-cm ruler. What would be the best way to
scientifically determine the thickness of a single sheet?
A) Look up the density of paper on the Internet, weigh the paper to determine its mass, and then measure the paper’s length and width. Use
these data and the definition of density (=mass/volume) to calculate the thickness of the paper.
B) Take a stack of 500 sheets, measure the height of the stack using the ruler, and divide this distance by 500.
C) Give the ruler to another scientist in exchange for the required information.
D) Call the manufacturer and ask for the information.
Interpreting data
35. During the autumn, a self-educated naturalist observes bears hibernate, birds fly south, and leaves change color. He concludes that bear
hibernation, bird migration, and changing leaf colors are the cause of winter. Do you agree or disagree with the naturalist, and why or why
not?
A) Agree; these events occur every autumn, just before winter.
B) Agree; all these events contribute to cooling and that brings about winter.
C) Disagree; winter is caused by the Earth moving farther from the sun.
D) Disagree; just because one event occurs before another that does not necessarily mean that the first causes the second.
Induction based on a set of data
36. A shopper goes to a store to purchase oranges. Not knowing which type is the sweetest, he purchases three varieties with these results:
Color
Size
Sweetness
dark orange
Medium
Somewhat sweet
medium orange
Small
Very sweet
light orange
Large
Not sweet
Which of the following is a correct conclusion about the sweetness of these oranges?
A) The darker the color of the orange, the sweeter it is.
B) The larger the orange, the sweeter it is.
C) The more expensive an orange, the sweeter it is.
D) None of the above conclusions about sweetness is correct.
Price (cents)
43
19
30
DET: Deduction from a law to make a prediction
37. A gas is in a constant volume container where the pressure (P) can be varied and temperature (T) easily measured to demonstrate the
P
 constant . Which of the following conditions could be demonstrated using this device?
T
A) As P goes up, T goes up.
B) As P goes up, T remains constant
C) As P goes down, T goes up.
D) As P goes 
down, T remains constant
following relationship:
CC: several competing hypotheses – which one is best?
38. A class of school students notices that a tree outside their classroom was losing its leaves. They wonder about the cause. They note that
the custodian waters the grass three times per week and that the water collects in a pool around the base of the tree. What would be the most
reasonable explanation for the cause of the loss of the tree’s leaves?
A) the grass is being over watered
B) the tree is drowning from too much water
C) the tree is dying from old age
D) a recent cold spell killed the leaves
CRT: interpret and analyze data
39. Which of the following graphs accurately displays the (X, Y) data points presented here? (0.5, 2); (1, 1); (2, 0.5); (4, 0.25)
A)
B)
C)
D)