|
Abstract
Since students are fascinated by television shows and movies
involving crime detection, using a forensic science approach could
be a motivational tool for engaging students in the four included
lessons. This approach for the analysis of blood spatter found at a
"crime scene" is used to teach process and inquiry skills, including
observation, measurement, and problem solving. The students will use
open-ended investigations to draw comparisons between common
phenomena and blood spatters. Using collected digital photos, an
unknown blood spatter drop pattern will be compared, contrasted, and
categorized.
Invitation/Fundamental Understandings:
Essential
Questions:
Knowledge and skills: Fundamental
Understanding:
* Much of the scientific understanding is
constructed through the
development of patterns and
generalizations.
*Analyzing measurements is one effective tool
used to create and
evaluate these patterns.
Essential
Questions:
1. How are water droplets and blood droplets the
same?
2. How does the trajectory, height, surface tension, and
impact surface of a falling liquid affect the observed
pattern?
3. How are measurements used in blood spatter
investigations?
4. What are the legal ramifications of blood
spatter analyses and how are these analyses used in forensic
investigation?
Skills: comparative analysis, measuring,
calculating, observing, graphing, collecting data, critical
thinking, making inferences, problem solving, using spreadsheets,
Internet research skills
Knowledge: measurement, angles,
trajectories, surface tension, experimental design, characteristics
of spatter patterns
Standards
National Standards NSES CONTENT
STANDARD: Unifying Concepts and Processes
TECHNOLOGY
STANDARDS:
Students use a variety of media and formats to
communicate information and ideas effectively to multiple audiences.
Students use technology to locate, evaluate, and collect
information from a variety of sources.
Students use
technology tools to process data and report results.
Students employ technology in the development of strategies
for solving problems in the real world.
INFORMATION LITERACY
STANDARDS:
Standard 1: The student who is information
literate accesses information efficiently and
effectively.
Standard 2: The student who is information
literate evaluates information critically and
competently.
Standard 3: The student who is information
literate uses information accurately and creatively.
Standard
7: The student who contributes positively to the learning community
and to society is information literate and recognizes the importance
of information to a democratic society.
State Standards Georgia: Process Skills
Nevada: Process Skills #19
Workforce Competencies: INFORMATION
MANAGERS (3.1) NUMERIC PROBLEM SOLVERS (3.3) CREATIVE AND CRITICAL
THINKERS (3.4) COOPERATIVE WORKERS (3.8)
Unit of Practice
Relevance:
Lies at the heart of the discipline: The core of good scientific
practices is scientific inquiry. The basis of science inquiry is
observation, data collection, and recognizing patterns. Represents a
big idea: Recognizing patterns is a life-long skill that students
can utilize in many different situations. The analyses represented
in this unit can be applied to real life situations using forensic
investigations. Misunderstandings: Many students may not realize
that there are multiple factors that affect the spatter patterns of
liquids. Engagement: Students have seen media accounts of crime
scene investigations. The unit provides students the opportunity to
participate in activities that culminate in the interpretation of
blood spatters at a crime scene.
Context
This unit is designed to be used in a high school science class.
Students will need to know the basics of experimental design.
Scientific method should be discussed prior to this lesson, as well
as the concepts of controlled and manipulated variables, data
collection, graphing, independent and dependent variables, and
measuring techniques. They should be familiar with the use of a
digital camera, a spreadsheet program, Internet research and a
graphing program.
Assessment
There will be formative assessments during the lessons such as a
check of the students' experimental design, their graphs and their
digital photo collection. A summative assessment will tie in all of
the lessons and give insight into the students' understanding of the
unit.
The students will produce a product at the culmination
of the fourth lesson that demonstrates their understanding of the
concepts addressed in this unit. The performance product that the
students turn in will be of their own choosing. It can be either a
formal lab report, a story, a forensics case study, a PowerPoint
presentation, or any other type of presentation adhering to the
parameters of the assignment.
In Lesson 1 dealing with
water, simulated blood, and two other liquids the students will draw
comparisons between blood and water properties of surface tension,
viscosity, and specific gravity. The teacher can check for
understanding by reviewing student responses to questions after this
guided inquiry activity. Lesson 2 involves Internet research of a
case study dealing with blood spatter patterns. The formative
assessment will be the teacher critique of a short paragraph written
by the student summarizing the case study. When the students
determine an appropriate experimental design in the third lesson,
the teacher will check for feasibility of the experiment. At the
point when the students are displaying their data, such as the
spreadsheet and the graphing activities, the teacher will check for
correct relationships. The students will be collecting digital
photos of their data that the teacher can also preview.
Components:
Lesson 1: Is Blood Thicker Than Water? In this lesson, students
will investigate water properties and compare them to simulated
blood properties. All students will be engaged by performing this
hands-on experiment. Students will show what they have learned by
answering questions in this guided inquiry lesson.
Lesson 2:
Whodunit? In this lesson, students will read a case study while in
small groups. They will write short paragraphs demonstrating what
they have learned by reading the information and responding to the
question: How is the information presented in the case study
important to the forensic investigation of the crime? How is
eyewitness testimony similar to forensic testimony? How is it
different? Which would have greater influence on a jury's decision?
Why?
Lesson 3: Pitter, Patter, Spatter Patterns In this lesson,
students will design their own experiment showing how differences in
height, impact surface, and angle affect the blood spatter patterns
produced. All students will be engaged as they work in small groups
to design and implement their procedures. Students will be taking
digital photos of the trials and developing a database from which to
compare the unknown spatter pattern in a subsequent lesson. They
will also need to display their collected data in a spreadsheet and
then graphically show their results.
Lesson 4: Murder Mystery: Catch
the Clues In this lesson, students will work in the same groups as
Lesson 3 and determine, by using the previous collected data, the
height, impact surface, and angle of impact for an unknown sample in
a mock crime scene. This lesson requires the students to make
measurements at the "crime scene" and do a comparative analysis with
information from Lesson 3. As a check for the accuracy of the
students' results, students will be introduced to the "string
method" for determining the origination of the blood spatter.
Additional Resources
Main
URL:
Related Resources
Related Lessons
Copyright © 1997-2003
Career Connection to Teaching with Technology
USDOE Technology Innovation Challenge Grant
Marshall Ransom, Project Manager
All rights reserved.
|
|
|
|
