Biology 1233 Chapter 1

statistics

A set of analytical and mathematical tools designed to help researchers gain understanding from the data they gather.

placebo

A substance which contains no medicine, but which the receiver believes is a medicine.

controlled experiment

An experiment in which an observer tests a hypothesis by looking for changes brought on a system by holding constant all variables but the one under observation. The evidence confirms or disproves the idea (hypothesis) used as an explanation for a natural event.

biological literacy

The ability to use the process of scientific inquiry to think creatively about real world issues, communicate those thoughts, and integrate them into decision making

cell theory

all organisms are composed of cells and all cells come from preexisting cells.

critical experiment

an experiment that makes it possible to decisively determine whether a particular hypothesis is correct.

placebo effect

poorly understood phenomenon in which people respond favorably to any treatment. It highlights the need for an appropriate control group.

variables

the characteristics of an experimental system that are subject to change. Ex: the amount of echinacea a person is given, or a measure of the coarseness of an individual's hair.

hypothesis

A proposed, scientifically testable explanation for an observed phenomenon.

experimental group

-a group of subjects who are exposed to a particular treatment. Ex: the individuals given echinacea rather than placebo.

control group

-a group of subjects who are treated identically to the experimental group, with one exception-they're not exposed to the treatment. Ex: The individuals given placebo rather than echinacea.

null hypothesis

-a hypothesis that states a lack of relationship between 2 factors. This is easier to disapprove. -A hypothesis (H0) that states a lack of relationship between two factors. The opposite of the alternative hypothesis, (H1). A hypothesis which the researcher tries to disprove, reject or _____. The '___' often refers to the common view of something, while the alternative hypothesis is what the researcher really thinks is the cause of a phenomenon. An experiment conclusion always refers to the ___, rejecting or accepting H0 rather than H1.

treatment

-any experimental condition applied to the research subjects. Ex: it might be the shaving of one of an individual eyebrows, or the pattern used to show "suspects (all at once or one at a time) to the witness of a staged crime.

The basic steps in the scientific method

1. Make observations 2. Formulate a hypothesis 3. Devise a testable prediction 4. conduct a critical experiment 5. draw conclusions and make revisions

research hypothesis

A proposed explanation for observed phenomena, in the form of a statement, created by researchers when they speculate upon the outcome of a research experiment that is testable, falsifiable and realistic.

anecdotal observation

Based on just one or a few observations people conclude that there is or is not a link between two things.

Pseudoscience

In which individuals make a scientific sounding claims that aren't supported by trustworthy, methodical scientific studies.

scientific prediction

Logical consequences of the hypothesis

Positive correlation

Meaning that when one variable (the# of firefighters) increases, so does the other (the severity of the fire).

scientific literacy

a general, fact-based understanding of the basics of biology and other scieces

empirical knowledge

based on experience and observations that are rational, testable, and repeatable

science

it is an intellectual activity, encompassing observation, description, experimentation, and explanation of natural phenomena.

randomized

in a research study, describes a manner of choosing subjects and assigning them to groups on the basis of chance. The subjects are randomly assigned into experimental and control groups.

double-blind experiment design

in which neither the experimental subjects nor the experimenter know which treatment a subject is receiving.

blind experiment design

in which the experimental subjects don't know which treatment (if any) they are receiving.

theory

is an explanatory hypothesis for natural phenomena that is exceptionally well supported by the empirical data.

dependent variable

is one that can also be observed and measured, but whose response is created by the process being observed and depends on the independent variable. Generally represented on the y-axis.

independent variable

is some entity that can be observed and measured at the start of a process, and whose value can be changed as required, generally represented on the x-axis

biology

the study of living things

scientific method

understanding achieved through the process of examination and discovery.