Chapter 2: Principles of Science and Systems Flashcards
Science
- The process of producing knowledge methodically and logically.
- A search for answers to questions.
- Develops and tests theories.
- Helps us understand the world and meet practical needs.
- It assumes that the universe, our world and nature are knowable.
What two things does science depends on?
Accuracy and Skepticism
Reproducibility
if one scientist conducts an experiment in a particular way finding particular results, his findings should be able to be reproduced by another scientist with the same results.
Replication
repeating the same study multiple times
Deductive Reasoning
logical reasoning from general to specific
Example: If you understand the Law of Gravitation, you know that an apple falling from a tree moves toward the ground
Inductive Reasoning
reasoning from many observations that help you to make a general rule
Example: We observe different bird species appearing
and disappearing in a specific location and as a general
rule decide that birds migrate to different locations.
How do you test a hypothesis?
- Observation leads to identification of a problem.
- Propose a hypothesis
- Test the hypothesis
- Gather data
- Interpret results, if the hypothesis was supported, draw conclusions. It the hypothesis was not supported, redesign the test.
- If the explanation holds up to repeated testing, you can develop a theory.
Probability
how likely something will occur
What are the types of experiments?
- Natural Experiment
- Manipulative Experiment
- Blind Experiment
- Double-Blind Experiment
Natural Experiment
involves observation of events that have already happened
Example: Mountain Building, Species Adaptations
Manipulative Experiment
conditions are deliberately altered to see what will happen; most are done in a laboratory under controlled conditions
Blind Experiment
researcher does not know which group is the control group (Example: Drug testing)
Double-Blind Experiment
both the researcher and test subject are unaware of who is in the test vs. control group
What are the two types of variables?
- Independant
- Dependant
The Independant Variable
This is the variable the researcher can manipulate
Plotted on the X-axis
The Dependant Variable
Also called the response variable because it “depends” on the independent variable
Plotted on the Y-axis
What are the types of models?
- physical
- mathematical
- mental
Physical Model
a model of an actual object
Mathematical Model
an equation
Mental Model
a model of an idea
Statistics
- They are numbers that let you evaluate and compare things
- A field of mathematics
- They allow us to find patterns in data
- They allow us to determine how “valid” our data is
Desciptive Statistics
help you assess the general state of a group
Begins with the calculation of an average for a group.
Mean = average value
Symbol for mean is X with a bar on top or the greek letter mu
Sample
a group of something
Standard Deviation
a calculation that allows you to know how far data deviates from an average score; it also allows you to establish a range for your data
System
a network of interdependent components and processes, with materials and energy flowing from one component of the system to another
Ecosystem
a complex assemblage of animals, plants and their environment through which materials and energy move
Open System
a system that receives input from its surroundings and produces outputs that leave the system; almost all natural systems are open
Closed System
a system that exchanges no energy or matter with its surroundings; these are rare
Throughput
term used to describe the energy and matter that flow into, through, and out of a system
Positive Feedback
a self-perpetuating process; a positive feedback loop is a situation in which a factor or condition causes changes that enhance that factor or condition
(Example: Bacteria get mercury poisoned. Fish eat bacteria so then fist get mercury poisoned. Humans eat fish, so humans get mercury poisoned.)
Negative Feedback
a process that supresses change; a negative feedback loop causes changes that reduce a factor or condition
(Example: Your body gets hot, so it sweats to cool down. Your body gets cold, so it makes hairs on arms erect to capture heat.)
Homeostasis
a tendency to remain stable and unchanging
Disturbances
events that can destabilize or change a system
Example: forest fire in an ecosystem
Resilience
the ability to recover from a disturbance
State Shift
conditions do not completely return to normal because the disturbance was so great
Scientific Consensus
a general agreement among scientists about a particular concept or principle
Paradigm Shift
term for a revolutionary change in scientific thinking
Pseudoscience
a collection of beliefs or practices mistakenly regarded as being based on scientific method
The worst nuclear accident in history occurred in which location?
Chernobyl, Ukraine
Statistics are used in:
analyzing data
A revolution is scientific thinking is known as:
a paradigm shift
An experiment in which a test group does not receive a variable is:
a controlled study
A testable explanation based on research alone is:
a hypothesis
The first calculation needed to determine the standard deviation of a set of values is the:
mean
