Scientific Thinking (Chapter 1)
Key definitions:
Biology: the study of living things
General scientific literacy: a general, evidence-based understanding of the basics of biology and other
sciences
Biological literacy: the ability to (1) use the process of scientific inquiry to think creatively about real-
world issues that have a biological component, (2) communicate these thoughts to others, and (3)
integrate these ideas into your decision-making.
Empirical: empirical knowledge is based on experience and observations that are rational, testable, and
repeatable.
Hypothesis: a proposed explanation for an observed phenomenon
●It must establish an alternative explanation for a phenomenon. That is, it must be clear that if
the proposed explanation is not supported by evidence or further observations, a different
hypothesis is a more likely explanation.
●It must generate testable predictions. This characteristic is important because we can evaluate
the validity of a hypothesis only by putting it to the test. This is, in fact, how science commonly
advances: we disprove hypotheses, which serves to increase our confidence in alternative
explanations. For example, we could disprove the “Eyewitness testimony is always accurate”
hypothesis by demonstrating that, in certain circumstances, individuals who have witnessed a
crime might misidentify the criminal.
●It is impossible to prove that a hypothesis is absolutely and permanently true: all evidence or
further observations that support a hypothesis are valuable, but future evidence might show that
the hypothesis is not true.
Null hypothesis: A hypothesis that states a lack of relationship between two factors
● Example: Echinacea has no effect on the likelihood of catching a cold or the duration of cold
symptoms.
Testable prediction: to propose a situation that will give a particular outcome if our hypothesis is true,
but will give a different outcome if our hypothesis is not true.
● Generally phrased in “If that is true… then I would expect” structure
Critical experiment: “an experiment that makes it possible to decisively determine whether a particular
hypothesis is better than the alternative hypotheses.”
Treatment: any experimental condition applied to the research participants. It might be the pattern used
to show “suspects” (all at once or one at a time) to the witness of a staged crime, or the dosage of
echinacea given to an individual.
