Scientific Method, Interpreting Data, Specificity of Terminology Flashcards
Science is _________ or ________
cyclical, iterative
What does cyclical/iterative mean?
The process keeps going and going, it repeats, continually adding to our knowledge
A body of existing knowledge is based on 3 things:
- Verifiable observations or descriptions- data from the natural world
- Repeatable measurements
- Synthesis
What are the 5 steps of the scientific method in order?
Observation -> Question -> Hypothesis -> Prediction -> Test
What does the scientific method rely on?
Empiricism
What is empiricism?
Evidence
What are the two types of logical reasoning processes the scientific method uses?
Inductive and Deductive Reasoning
What is Inductive Reasoning?
Results in a general conclusion, broad generalizations, and/or theories based on a body of observations
A “bottoms-up” approach, beginning with observations
Probabilistic
What is Deductive Reasoning?
Goes from general concepts and/or specific observations to a focused conclusion
A “top-down” approach beginning with theory
A scientific hypothesis is what kind of explanation of an observation?
Tentative Mechanistic Explanation
Mechanistic explanation is when a phenomenon is explained by identifying the mechanisms that generate that phenomenon by specifying the underlying parts, their organization, and their interaction
A scientific hypothesis needs to be _______ and _______
Testable and falsifiable
A scientific hypothesis usually answers what question
Why?
What does a scientific hypothesis always include?
A because statement
What is circular logic?
Explaining that X will happen because X will happen
What is a prediction?
A statement of what will happen if your hypothesis is correct, given a specific set of experimental circumstances
A prediction outlines how to test a hypothesis by specifying what?
The independent and dependent variables
What is a variable?
A factor if interest to scientists that can change
What is an independent variable?
What the scientist changes to understand its effects on the system
What is a dependent variable?
How the scientist measures the system’s response to the independent variable
What is the template for beginning a prediction?
“If the hypothesis is correct, then…”
Why should a hypothesis be generalized?
If it’s not generalized, it limits the ability to test it to a single experiment
What is a control group?
A group that does NOT receive the treatment, but is identical in all other ways to the treatment groups and serves as a point of comparison
What is a confounding variable?
A factor that affects the result that was not controlled for
Why should experiments be repeated on many different test groups?
To ensure that results aren’t caused by random events and to represent a population mean (average) response
Why are confounding variables important?
Because you need to try to anticipate them and include them in experimental design.
What is pseudoreplication?
When treatments are either not replicated or not independent
Called pseudoreplication because the experiment appears replicated, but is not because the samples are not truly independent of each other
What is a replicate?
The smallest experimental unit to which a treatment can be applied
How are statistical inferences made?
About the means of responses
Normal distribution is the most common
How do you get more precise distribution?
By increasing the sample size (N)
When does the strength of a conclusion increase?
When the number of observations used to form the conclusion increases
What is a scientific conclusion based on?
Evidence
What do figures and tables provide?
All the information needed to interpret the relationship between dependent and independent variables
What does a conclusion result from?
1 study testing 1 hypothesis
What does science never do?
Prove something
Why does the scientific method not prove hypotheses? (3 reasons)
- Experimental data either supports or does not support hypothesis
- Hypotheses must be falsifiable
- Uses quantifiable and justifiable measurements to either support or reject (disprove) hypothesis
What are the three properties of a theory?
- Unifies many ideas/hypotheses
- Broad in scope
- Extremely highly supported by evidence from many experiments
What are the two properties of a conclusion?
- Results from a single experiment that tested a single hypothesis
- May support or refute the hypothesis
What question is the Cell Theory answering?
What are organisms made of?
What question does the Theory of Evolution by Natural Selection answer?
Where do organisms come from?
What question does the Chromosome Theory of Inheritance answer?
How is hereditary information transmitted from one generation to the next?
What does Germ Theory describe?
How micro-organisms act as pathogens to cause disease
Definition of hypothesis
A proposed general mechanistic explanation of an observation and its relationships that is testable and falsifiable
Definition of theory
An accepted hypothesis or group of hypotheses that is falsifiable
Definition of scientific law
A description of a generalized body of information that doesn’t answer “why”
Definition of fact
An observation that has been repeatedly confirmed and for all practical purposes is accepted as “true”
Truth in science is never final
What should a hypothesis contain? (2 things)
- A “because” statement that provides an explanation
- Information about the initial observation
What should a hypothesis not contain? (2 things)
- Information about the specific experiment you will use to test it
- Circular logic as a part of the explanation
What should a prediction include? (3 things)
- Information about the specific experiment you will use to test the hypothesis
- The independent and dependent variable(s)
- An “if the hypothesis is correct, then…” template
What should a prediction not include? (1 thing)
A “because” statement that provides an explanation
What happens after completing the scientific method?
Repeat the experiment (or one very close in design)
Report the results (publish in a scientific journal)
Other researchers then test the same hypothesis
New questions are formed and followed by new experiments
What is important to maintain after the scientific method is complete?
Healthy skepticism
How long should you maintain healthy skepticism?
Until enough data is generated to make a reasonable judgement or interpretation
What are the three properties of a scientific journal article?
- Peer-reviewed
- Considered authoritative repository on information
- Archived in some form (usually paper)
When three things should you consider when looking at an online scientific journal articled?
- It should be considered and cited as per paper version
- Check to make sure it’s from an accredited journal
- Consider the Impact Factor- the average number of citations of the article in the previous two years
What is wrong with the statement “clinically proven”
Science does not “prove” hypotheses
If the trial is conducted according to proper scientific method, then the hypothesis is either supported or not supported by the data
What are the reasons why it’s estimated that 90% of published medical research is wrong?
Sloppy statistics
Inadequate study sample size and duration
Bias (conscious and unconscious)
Inadequate replication (single study, statistical significance (chance something is due to a random event or something of significance), etc.)
What is cherry picking data?
When data is selected/omitted to support hypothesis
How can you defend against cherry picking data?
- Consider alternate hypotheses
- Consider who funded the study
- Consider context of observations
- Ask to see the data
_______ results in _________, but __________ doesn’t imply _________
(correlation and causation)
Causation results in correlation, but correlation doesn’t imply causation
What is the Fundamental Scientific Controversy?
When scientists disagree about a central theory
Considers the proportion of scientists and data supporting the theory
What is the Secondary Scientific Controversy?
When scientists disagree, not about IF a central theorem is supported, but HOW mechanisms in a central theorem work
What is false equivalency?
Putting a credible source up against a source that is clearly not credible and saying something like “we’re just hearing two different points of view”
What impression can false equivalency give?
The false impression that some of the myths being presented are believed by a large portion of the scientific community
What is the basal rate fallacy?
When relevant statistical information is ignored in favor of case-specific information
What does one opinion or one study not do?
It neither defines nor disproves a theory or principle, but only adds to the body of information that it needs to be weighed against
