AP Bio: Intro to Biology

Chi-square test

a statistical test used to determine the probability of obtaining observed proportions by chance, under a specific hypothesis

critical value

The dividing point between the region where the null hypothesis is rejected and the region where it is not rejected.

deductive reasoning

reasoning in which a conclusion is reached by stating a general principle and then applying that principle to a specific case (general to specific)

degrees of freedom

The number of individual scores that can vary without changing the sample mean. Statistically written as 'N-1' where N represents the number of subjects.

dependent variable

The measurable effect, outcome, or response in which the research is interested.

Experimental hypothesis (H1)

a testable prediction between the IV and the DV

independent variable

The experimental factor that is manipulated; the variable whose effect is being studied.

inductive reasoning

A type of logic in which generalizations are based on a large number of specific observations. (specific to general)

negative control

Control group where conditions produce a negative outcome. Negative control groups help identify outside influences which may be present that were not accounted for when the procedure was created.

null hypothesis

the hypothesis that there is no significant difference between specified populations, any observed difference being due to sampling or experimental error.

p-value

The probability level which forms basis for deciding if results are statistically significant (not due to chance). Usually .05

positive control

Group expected to have a positive result, allowing the researcher to show that the experimental set up was capable of producing results.

Reductionism

studying complex systems by looking at their simpler components that are more manageable to study

systems biology

An approach to studying biology that aims to model the dynamic behavior of whole biological interactions based on a study of the interactions among the system's parts.

theory

well-tested explanation that unifies a broad range of observations

Theory

well-tested explanation that unifies a broad range of observations