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The scientific method

Biologists study the living world by posing questions about it and seeking science-based responses. This approach is common to other sciences as well and is often referred to as the scientific method. The scientific method was used even in ancient times, but it was first documented by England’s Sir Francis Bacon (1561–1626) ( [link] ), who set up inductive methods for scientific inquiry. The scientific method is not exclusively used by biologists but can be applied to almost all fields of study as a logical, rational problem-solving method.

Painting depicts Sir Francis Bacon in a long robe.
Sir Francis Bacon (1561–1626) is credited with being the first to define the scientific method. (credit: Paul van Somer)

The scientific process typically starts with an observation (often a problem to be solved) that leads to a question. Let’s think about a simple problem that starts with an observation and apply the scientific method to solve the problem. One Monday morning, a student arrives at class and quickly discovers that the classroom is too warm. That is an observation that also describes a problem: the classroom is too warm. The student then asks a question: “Why is the classroom so warm?”

Proposing a hypothesis

Recall that a hypothesis is a suggested explanation that can be tested. To solve a problem, several hypotheses may be proposed. For example, one hypothesis might be, “The classroom is warm because no one turned on the air conditioning.” But there could be other responses to the question, and therefore other hypotheses may be proposed. A second hypothesis might be, “The classroom is warm because there is a power failure, and so the air conditioning doesn’t work.”

Once a hypothesis has been selected, the student can make a prediction. A prediction is similar to a hypothesis but it typically has the format “If . . . then . . . .” For example, the prediction for the first hypothesis might be, “ If the student turns on the air conditioning, then the classroom will no longer be too warm.”

Testing a hypothesis

A valid hypothesis must be testable. It should also be falsifiable    , meaning that it can be disproven by experimental results. Importantly, science does not claim to “prove” anything because scientific understandings are always subject to modification with further information. This step—openness to disproving ideas—is what distinguishes sciences from non-sciences. The presence of the supernatural, for instance, is neither testable nor falsifiable. To test a hypothesis, a researcher will conduct one or more experiments designed to eliminate one or more of the hypotheses. Each experiment will have one or more variables and one or more controls. A variable    is any part of the experiment that can vary or change during the experiment. The control group contains every feature of the experimental group except it is not given the manipulation that is hypothesized about. Therefore, if the results of the experimental group differ from the control group, the difference must be due to the hypothesized manipulation, rather than some outside factor. Look for the variables and controls in the examples that follow. To test the first hypothesis, the student would find out if the air conditioning is on. If the air conditioning is turned on but does not work, there should be another reason, and this hypothesis should be rejected. To test the second hypothesis, the student could check if the lights in the classroom are functional. If so, there is no power failure and this hypothesis should be rejected. Each hypothesis should be tested by carrying out appropriate experiments. Be aware that rejecting one hypothesis does not determine whether or not the other hypotheses can be accepted; it simply eliminates one hypothesis that is not valid ( [link] ). Using the scientific method, the hypotheses that are inconsistent with experimental data are rejected.

Questions & Answers

what is ecology
volex Reply
show the diagram of sponge
Favour Reply
explain the processes found in a carbon cycle
Elvas Reply
photosynthesis;this is the process by which grean plants make there own food by using carbon,oxygen, sunlight in the precess of chlorophyll combusion ;this is the process by which fossil fuels are converted in form of a gas of carbon dioxide by an enzyme called a foillitrrion respiration;a proces
Mwansa
Respiration;this is a process by which living organism release energy from food there eat
Mwansa
decoposition;this process is carried by dead matters or decomposes such as bacteria and fungi where dead matters decay buried for thousand of years excretions the remove of toxic metabolism waste product from the body through excretory or gain such as anus and skin etc
Mwansa
also tarnspiratiom where by a plant losses water inform of water vapour into the at mosphere by rhisombium ezyme
Mwansa
so not enzyme but bacteria
Mwansa
sorry not enzyme but bacteria
Mwansa
what is a base?
Alice Reply
base can be define as the anatomy of structure
Ogundipe
what are somatic cells
KAKU Reply
Somatic cells responsible for making the body
Ahsan
vegetative cells, they divide by mitosis.
Ishitha
what is angiosperms
Papillon Reply
what is the function of bile
Papillon
what is neurologist
Benjamin Reply
A neurologist is a brain doctor,a physician who diagnose and treat all categories of conditions and disease involving the central and peripheral nervous system eg.covering, blood vessels and all effector tissue such as muscle
Favour
what is a cell
God Reply
is a basic unit of living organism
Mwansa
or a basic building blocks of all living things
Mwansa
explain cell biology
Grace Reply
cell biology is a biology branch which study about function,size,definition ,....of cells.
fitsum
what are endotherms
angelina Reply
pls can someone elaborate more on biomagnification
angelina
Hey,what?
Peter
Biomagnification, also known as bioamplification or biological magnification, is any concentration of a toxin, such as pesticides, in the tissues of tolerant organisms at successively higher levels in a food chain.
chance
An endotherm (from Greek ἔνδον endon "within" and θέρμη thermē "heat") is an organism that maintains its body at a metabolically favorable temperature, largely by the use of heat set free by its internal bodily functions instead of relying almost purely on ambient heat.
chance
these are substances that absorbs heat energy
Alice
What diffusion
Oseres Reply
it is the movement of water molecules from the region of higher concentretion to a region of lower concentration
Lukas
is the movement of anything from region of higher concentration to a region of lower concentration.
chance
is a movemnt of H2O molecule from a region of higher concentration to the legion of lower Concentration.
Benjamin
diffusion is the movement of particles from a region of higher concentration to a region of lower concentration resulting into an even distribution
Alice
is the movement of water molecules,ions from the region of higher concentration to the region of lower concentration in a semi permeable membrane.
Favour
pls I don't know how to read very well so how can I understand all this
Mercy Reply
But you wrote all this ur self so please continue till you become perfect thanks
Favour
What's succession
Talabi Reply
an acid is a substance that produces hydrogen ions in an aqueous solution
angelina Reply
how? give a reason to support ur answer
SSEJJO
Types of acids and there definitions
SSEJJO
what is acid
asaa Reply
An acid is a substance which gives Hydrogen ions in aqueous solutions.
Ahsan
food poison
asaa
an acid is a chemical substance that produces or gives out hydrogen ions as the only positively charged ion when dissolved in water
Alice
what is salt?
Basit
a sait is a substance formed when hydrogen ions in an acid are partially or fully replaced by a metal or ammonium ions
Alice
When an acid and base react chemically, a salt is form.
Ahsan
what is nervous system
kumkum

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Source:  OpenStax, Biology. OpenStax CNX. Feb 29, 2016 Download for free at http://cnx.org/content/col11448/1.10
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