Chapter 1 Flashcards
What is an observational study?
A study in which characteristics of a sample are measured without manipulating variables
What are the 3 types of observational studies?
- Cross sectional - a type of observational study that collects data from a sample of subjects just once at a certain point in time.
- Case-control - a type of observational study that compares a group of subjects having a trait of interest (cases) with a group of similar subjects not having the trait (controls).
- Cohort - an observational study in which a group of similar subjects (the cohort) is selected at the start of the study and then followed over time.
What is correlation
Correlation is an association between two variables in which a change in one variable is associated with a change in the other variable. Correlation may be strong or weak. It can also be positive or negative.
What are 4 reasons to do observational studies?
-Feasibility
-Cheaper
-Easier
-More subjects
An observational study may be the only type of study that is feasible for certain research questions because experiments are impossible, impractical, or unethical to undertake.
An observational study is generally cheaper and easier to conduct than an experimental study.
An observational study usually can study more subjects and obtain a larger set of data than an experimental study.
What is a model?
A model is a representation of part of the real world.
Like a hypothesis, a model must be evaluated.
What is a model organism?
A model organism is a nonhuman species that is extensively studied to understand particular biological phenomena.
Broad review
Science is a distinctive way of gaining knowledge about the natural world that is based on the use of evidence to logically test ideas. As such, science is more of a process than a body of knowledge.
A scientific theory, such as the germ theory of disease, is the highest level of explanation in science. A theory is a broad explanation for many phenomena that is widely accepted because it is supported by a great deal of evidence.
The scientific investigation is the cornerstone of science as a process. An investigation is a procedure for gathering evidence to test a hypothesis.
A scientific experiment is a type of scientific investigation in which the researcher manipulates variables under controlled conditions to test expected outcomes. Experiments are the gold standard for scientific investigations and can establish causation between variables.
Nonexperimental scientific investigations such as observational studies and modeling may be undertaken when experiments are impractical, unethical, or impossible. Observational studies generally can establish correlation but not causation between variables.
Science. What do it mean?
Derived from latin word: scientia - meaning - knowledge or to know.
What is science NOT about?
Being right. Science is about seeking the truth,
Science is two things. What are they?
Organized and reliable knowledge about the natural world.
AND
The process used to acquire knowledge.
What are the steps in the scientific method?
Observe and generalize
Make hypothesis
Make a testable prediction
Experiment or observe
Modify hypothesis
How to observe and generalize?
Use inductive reasoning by making generalizations and observations.
What is a hypothesis?
A testable prediction
Can a hypothesis be proved true?
No, only supported or disapproved
ways to share scientific data?
Peer-reviewed journals
and
Popular press
and
Electronic publications
