1. A single seismograph can determine how far away an earthquake has occurred but not exactly
where. Explain, with the aid of a diagram, why it is necessary to obtain information from three
different seismograph sites to locate the epicenter of an earthquake.
NAEP released item, grade 12
Scoring Guide
Score & Description
Complete
Student response recognizes that both distance and direction are needed to locate an earthquake.
A sketch is drawn showing a circle, or circular arc around three points that represent the locations
of the seismograph sites. The radius of each circle represents the distance to the epicenter for each
site. At least two of the circles should intersect in two places showing the need for a third
seismograph to distinguish between the two. The epicenter will be located where the three circles
intersect. Arcs are acceptable. Student's sketch shows 3 lines with measured distances meeting at
the epicenter.
Partial
Student response recognizes that both distance and direction are needed to locate an earthquake.
They (may) talk about the intersection or meeting of the three distances. No diagram or diagram
may be close [flawed in some way, e.g., uses area instead of distance, circles not linked to position
of seismograph, concentric circles around seismographs].
Unsatisfactory/Incorrect
Student response shows no understanding of the triangulation method for locating earthquake
epicenters, or cannot explain that distance and direction are both needed for location purposes, or
draws an incorrect or irrelevant diagram.
NAEP released item, grade 12
Complete - Student Response
1 A single seismograph can determine how far away an earthquake has occurred but not exactly
where. Explain, with the aid of a diagram, why it is necessary to obtain information from three
different seismograph sites to locate the epicenter of an earthquake.
1 A single seismograph can determine how far away an earthquake has occurred but not exactly
where. Explain, with the aid of a diagram, why it is necessary to obtain information from three
different seismograph sites to locate the epicenter of an earthquake.
NAEP released item, grade 12
Scorer Comments:
Both responses provide complete explanations with drawings that demonstrate how three
seismograph sites are used to determine the location of the epicenter of an earthquake.
Partial - Student Response
1 A single seismograph can determine how far away an earthquake has occurred but not exactly
where. Explain, with the aid of a diagram, why it is necessary to obtain information from three
different seismograph sites to locate the epicenter of an earthquake.
NAEP released item, grade 12
1 A single seismograph can determine how far away an earthquake has occurred but not exactly
where. Explain, with the aid of a diagram, why it is necessary to obtain information from three
different seismograph sites to locate the epicenter of an earthquake.
NAEP released item, grade 12
Scorer Comments:
The first response provides an incomplete explanation, including a drawing that lacks an indication
of the distance between the seismograph site and the epicenter. The second response provides an
incomplete explanation, including a drawing that lacks intersecting circles or arcs.
1
Unsatisfactory/Incorrect - Student Response
A single seismograph can determine how far away an earthquake has occurred but not exactly
where. Explain, with the aid of a diagram, why it is necessary to obtain information from three
different seismograph sites to locate the epicenter of an earthquake.
NAEP released item, grade 12
1
A single seismograph can determine how far away an earthquake has occurred but not exactly
where. Explain, with the aid of a diagram, why it is necessary to obtain information from three
different seismograph sites to locate the epicenter of an earthquake.
NAEP released item, grade 12
Scorer Comments:
Neither response provides a drawing or explanation that recognizes that distance and direction are
needed to locate an earthquake.
NAEP released item, grade 12
2005 National Performance Results
Score
Percentage of Students
Unsatisfactory/incorrect
Partial
Complete
61%
12%
6%
Omitted
Off task
17%
4%
Note:
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These results are for public and nonpublic school students.
Percentages may not add to 100 due to rounding.
The Fields of Science: Earth & Space Sciences (Sub content classification: Solid Earth)
Knowing and Doing Science : Conceptual Understanding
NAEP released item, grade 12
The Fields of Science
Earth & Space Sciences
This question measures basic knowledge and understanding of the following:
Solid Earth
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Composition of the Earth;
Forces that alter the Earth's surface;
Rocks: their formation, characteristics, and uses;
Soil, its changes and uses;
Natural resources used by humankind; and
Forces within the Earth (not in grade 4).
Knowing and Doing Science
Conceptual Understanding
Conceptual understanding includes the body of scientific knowledge that students draw upon when
conducting a scientific investigation or engaging in practical reasoning. Essential scientific concepts
involve a variety of information, including facts and events the student learns from both science
instruction and experiences with natural environment; and scientific concepts, principles, laws, and
theories that scientists use to explain and predict observations of the natural world.
NAEP released item, grade 12