The Scientific Method and The Hierarchy Of Evidence Flashcards
What is science?
The intellectual and practical activity encompassing the
systematic objective study of the structure and behaviour of the physical and natural world through observation and experiment
List some adjectives used to describe scientists.
Objective Well-informed Tenacious Open-minded Skeptical Data-driven Flexible
What does objective mean?
Objective: not influenced by personal feelings or opinions in considering and representing facts
What does subjective mean?
Based on or influenced by personal feelings, tastes, or opinions
Give an example of something that is objective.
The patients temperature is 39.1 degrees Celsius
Give an example of something that is subjective.
I really like that song
Define skepticism.
An attitude of doubt or a disposition to incredulity either in general or toward a particular object
Define credulity
Readiness or willingness to believe especially on slight or uncertain evidence
What is cynicism?
A mistrust of the motivations behind a statement
What is falsifiability?
Falsifiability defines the testability of any scientific hypothesis
In other words, it must be possible to test it, if it is to be accepted
Give an example of a statement that is unfalsifiable.
There is a china Teapot (too small to be seen by a
telescope) in an ellipitcal orbit around Pluto
What is dogmatism?
Basing conclusions on authority rather than logic
Give an example of a dogmatic statement.
How do we know the earth is round? -> my parents told me (not because of photographs from space etc.
List the seven steps in the scientific method.
Problem/Question Observation/Research Formulate a Hypothesis Experiment Collect and Analyze Results Conclusion Communicate the Results
What is a hypothesis?
1/2
A testable‚ tentative answer to a question
A testable statement accounting for a set of observations
What is a scientific theory?
A Scientific Theory is a well-substantiated explanation of some aspect of the natural world, based on a body of facts that have been repeatedly confirmed
Give three examples of scientific theories.
Theory of evolution
Theory of gravity
Germ theory of disease
What are the two main types of error?
Type 1: Believing a falsehood (false positive)
Type 2: Rejecting a truth (false negative)
Give an example of a type 1 error.
A rain dance will bring rain - False, but relatively benign
Give an example of a type 2 error.
That rustling in the bushes is not a poisonous snake
- False, and deadly
List the different data types.
Quantitative
Qualitative
What is quantitative data?
Information about quantities
What is qualitative data?
Descriptive, subjective or difficult to measure
Give an example of a type of information that is not data.
3
Anecdotal evidence is not data
Using personal experience or an isolated example instead of a valid argument, especially to dismiss statistics.
“They say smoking kills but my grandfather smoked 60 a day and lived to 90
List in descending order the hierarchy of evidence.
7
Meta analysis and systematic reviews
Randomised controlled trials
Cohort studies
Case-control studies
Cross-sectional studies
Animal trials and in vitro studies
Case reports, opinion papers, and letters
List some examples of non scientific evidence.
Youtube videos
Gut feelings
Some guy you know
Personal anecdotes
What are Case-reports, opinion papers & letters?
2
Usually formed/published by experts in the field.
May be based on a single patient/experiment.
What are Animal trials & In-vitro (in glass) studies?
2
Studies performed on isolated microorganisms, cells or biological molecules outside of their normal context
or…
Studies performed in animals as a substitute for human subjects.
Remember – mice and humans are different!
What are cross-sectional studies?
2
Cross sectional studies determine the prevalence of a particular trait in a particular population at a particular time.
These studies are observational only.
What are case-control studies?
2
Case-control studies are also observational, and they work somewhat backwards from how we typically think of experiments.
They start with the outcome, then try to figure out what caused it. e.g. Gather people that have had heart attacks, and then look at their diets retrospectively
What are cohort studies?
In a cohort study, you take a group of people who do not have the outcome that you are interested in (e.g., heart disease) and who differ (or will differ) in their exposure to some potential cause.
Then, you follow them for a given period of time to see if they develop the outcome that you are interested in
What are randomised control trial.
3
The gold standard of scientific research.
Gather subjects that are as similar as possible, divide into groups.
Give one group a placebo, the other a treatment. Ideally they should be double-blinded.
Give an example of a randomised control trial.
A drug trial
Explain the process of a randomised drug trial.
4
Randomly split a group of patients into equal numbers– same sex ratio, age, no confounding factors etc.
Give one group the drug and one group a placebo
N.B. Doctor does not know which group is which
Patient does not know which group they are in
After some time, measure the effects
What are meta-analysis?
2
These are not experiments themselves, but rather are reviews and analyses of previous experiments.
Meta-analyses combine the data sets from multiple papers and run a statistical analyses across all of them
Give an example of a group which organises meta-analysis.
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