Transcript Chapter 8 Laboratory

Chapter 8: Laboratory and Field Work
Objectives:
1. Define and give purpose for lab and field work
2. Discuss and construct exercises in five lab approaches
3. Discuss elements of pre- and post-lab discussions
4. Describe teaching tips for successful labs
5. Plan productive and safe field trips
I.
Defining Laboratory Work
A.
Engages students in finding out first hand
1.
2.
3.
B.
Involves asking questions, making observations, proposing
solutions, making predictions, organizing data, explaining patterns
Can be used to improve technical skills
May involve specialized equipment
Central to science instruction
1.
2.
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4.
Shows students what scientists actually do
Develop a better understanding of concepts and principles
Provides concrete experiences
Promotes:
a.
b.
c.
d.
C.
Attitudes towards science
Scientific inquiry
Conceptual development
Technical skills
Concerns
1.
2.
3.
Often aimless, trivial, and badly planned
Periods too short, students often don’t complete the lab, lack
materials
Should promote inquiry, not be “cookbook” only
II.
Approaches to Laboratory Work
A.
Science process skills
1.
2.
3.
Learning skills, not content, is sometimes the primary goal of a lab
Often addressed at the beginning of a science course
Mental processes associated with science:
a.
b.
c.
d.
e.
B.
Observing and Inferring
i.
p. 152 gives an example exercise
ii. Observing = noting something with senses or an instrument
iii. Inferring = explaining what you observe
Measuring: p. 153 give creative example of a practice exercise
Hypothesizing = general statement about set of phenomena
Communicating
Experimenting = trying something out
i.
Can be controlled, where only one variable is allowed to change
ii. Independent variable = what is changed
iii. Dependent variable = what you are measuring
Deductive or Verification Lab
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2.
3.
Confirm concepts already presented in class
Convince students through concrete, personal experience
Try to avoid cookbook by allowing some freedom to try things
C. Inductive Laboratory
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2.
3.
4.
Develop experience with a concept before formal instruction
Students search for unknown patterns and principles
Example box 8.2, figure 8.4, and figure 8.5
Learning cycle (5E lesson plan) exploration step prior to explanation
encourages the use of inductive labs
D. Technical Skill Laboratory
1. Manipulative and hand-eye coordination skill important to science
2. Teachers should master all skills in the content area (p. 158)
3. Examples:
a. Care and use of microscopes is very important to biology students
b. Measuring voltage and current important in physics
4. Diagrams, graphs, drawings are important in all sciences
5. Struggling with basic skill impedes learning concepts in lab
E. Problem-Solving Lab
1. Allow students to participate in selecting problem (insect to study)
2. Students typically understand better when organizing own learning
3. Can serve to motivate low or high-achieving students
III. Preparing Students for Lab
A.
Pre-lab discussion
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5.
B.
Giving directions
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3.
4.
C.
Inform students why, how, and what they will be doing
Should explain how lab related to topic currently under study
If inductive lab, don’t give away the principle
May include demonstration of new techniques or equipment
Labs are less cookbook if student know what to look for
Need to be explicit and contain safety information
Oral instructions are fine for one-step activities: test pH with paper
Distribute written instructions or write on chalkboard if complex
May include questions for students to answer at certain points
Post-lab discussion
1.
2.
Often rushed or ignored due to lack of time
Critical to students crystallizing what they have learned
3.
Suggested post-lab activities
a.
b.
c.
d.
View and analyze data and observations
Have students explain data and how it demonstrates concepts
Check student misconceptions; they don’t always “get it”
Discuss science process skills to connect lab with science/technology
IV. Teaching Tips for Successful Labs
A.
Relevance of Lab work
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2.
3.
B.
Lab can become disconnected from course content, everyday lives
Use of commonplace equipment (xylophone, candles, household
chemicals) provide connection to reality (Rubin, 1988)
Make sure lab is tied to content taught in other ways
Structure in Lab activities
1.
2.
3.
Short exercises with plenty of direction seem to work best at first
Students become frustrated if they “don’t know what to do”
Some less structured labs facilitate problem solving, conceptual
change, and motivation. Can be incorporated later in a course.
C. Student Recording and Reporting of Data
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2.
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4.
Try to keep is simple so most time is spent on the experiment
Most manuals provide space for student data collection
Should vary, just as complexity of labs vary
Open-ended or inquiry labs may require more in-depth reporting
a. Typical format: problem, materials, procedure, results, conclusions
b. Often quite time-consuming to grade
5. De-emphasize correctness of data and conclusions, emphasize
process skills
D. Management and Discipline
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2.
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7.
Arrange for enough space and to keep materials away until needed
Individual work is best, but not always feasible
Groups often promote off-task activities: assign roles
Noise can be a problem in the less structure lab environment
Continuous contact with teacher can help: walk around, don’t sit
Rules and policies should be developed and discussed prior to lab
Example set of policies p. 165
E.
Evaluation
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2.
3.
4.
V.
Items to grade: lab exams, reports, notebooks, behavior, effort
Lab exams should be short and should reinforce concept learning
Lab practicals = stations with skills, techniques evaluated
Effort and behavior should count significantly, especially in middle
school
Field Work
A.
Contributes to scientific literacy
1.
2.
B.
Authentic learning experiences
Often the most memorable and enjoyable activities
Planning a Field Trip
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6.
Hospitals, power plants, factories, wildlife refuges are possibilities
Selection must be based on connection to curriculum
Survey possible sites prior to trip; often areas right around the
school can provide natural environment needed (p. 167)
Consult administrators for permission and policies
Make sure students know exactly what to do once in the field
In-class activities before and after maximize educational benefits