Goal 1 - Scientific Method / Graphing
The Scientific Method
Goal 1 (Reading in book pages 3, 11-17, 1099-1101)
What is Biology?
The Study of Life
“bio” = life or living
“ology” = to study
The knowledge obtained when scientists answer one question often generates other questions or proves useful in solving other problems
The common steps that biologists and other scientists use to gather information and answer questions are collectively known as scientific method.
Goal 1 (Reading in book pages 3, 11-17, 1099-1101)
What is Biology?
The Study of Life
“bio” = life or living
“ology” = to study
The knowledge obtained when scientists answer one question often generates other questions or proves useful in solving other problems
The common steps that biologists and other scientists use to gather information and answer questions are collectively known as scientific method.
Scientific methods usually begin with scientists identifying a problem to solve by observing the world around them.
A hypothesis is an explanation for a question or a problem that can be formally tested.
Eventually, the scientist may test a hypothesis by conducting an experiment.
To a scientist, an experiment is an investigation that tests a hypothesis by the process of collecting information under controlled conditions
Some experiments involve two groups: the control group and the experimental group.
1. The control is the group in which all conditions are kept the same.
2. The experimental group is the test group, in which all conditions are kept the same except for the single condition being tested.
In a controlled experiment, only one condition is changed at a time.
However, not all investigations are controlled.
Biologists use a variety of tools to obtain information in an investigation.
A hypothesis is an explanation for a question or a problem that can be formally tested.
- Hypothesizing is one of the methods most frequently used by scientists
- A hypothesis is not a random guess.
Eventually, the scientist may test a hypothesis by conducting an experiment.
- The results of the experiment will help the scientist draw a conclusion about whether or not the hypothesis is correct.
To a scientist, an experiment is an investigation that tests a hypothesis by the process of collecting information under controlled conditions
Some experiments involve two groups: the control group and the experimental group.
1. The control is the group in which all conditions are kept the same.
2. The experimental group is the test group, in which all conditions are kept the same except for the single condition being tested.
In a controlled experiment, only one condition is changed at a time.
- The condition in an experiment that is changed is the independent variable, because it is the only variable that affects the outcome of the experiment.
- While changing the independent variable, the scientist observes or measures a second condition that results from the change.
- This condition is the dependent variable, because any changes in it depend on changes made to the independent variable.
- Controlled experiments are most often used in laboratory settings.
However, not all investigations are controlled.
- An investigation such as this, which has no control, is the type of biological investigation most often used in field work.
Biologists use a variety of tools to obtain information in an investigation.
- Common tools include beakers, test tubes, hot plates, petri dishes, thermometers, balances, metric rulers, and graduated cylinders
- More complex tools include microscopes, centrifuges, radiation detectors, spectrophotometers, DNA analyzers, and gas chromatographs
Safety is another important factor that scientists consider when carrying out investigations.
Information obtained from investigations is called data.
Often, data are in numerical form
Tables and graphs help organize data so it can be interpreted more easily.
A graph is a diagram that shows relationships among variables.
- A safety symbol is a symbol that warns you about a danger that may exist from chemicals, electricity, heat, or procedures you will use.
Information obtained from investigations is called data.
Often, data are in numerical form
- Numerical data may be measurements of time, temperature, length, mass, area, volume, or other factors. Numerical data may also be counts.
- Sometimes data are expressed in verbal form, using words to describe observations made during an investigation.
Tables and graphs help organize data so it can be interpreted more easily.
- Tables are composed of several components – a title describing the contents of the table, columns and rows that separate and organize information, and headings that describe the information in each column of row.
A graph is a diagram that shows relationships among variables.
- Line graphs – used to show the relationship between two variables. Independent variable plotted on the X-axis and the dependant variable plotted on the y-axis.
- Bar graphs – Used to show comparison among data or to display data. Independent variable plotted on the X-axis and the dependant variable plotted on the y-axis. Plot data by drawing thick bars from the x-axis up to the y-axis data point.
- Circle graphs – consists of a circle divided into sections that represent parts of a whole. When all the sections are placed together the equal 100 % of the whole.
After careful review of the results, the scientist must come to a conclusion:
After results of an investigation have been published, other scientists can try to verify the results by repeating the procedure.
When a hypothesis is supported by data from additional investigations, it is considered valid and is generally accepted by the scientific community.
In science, a hypothesis that is supported by many separate observations and investigations, usually over a long period of time, becomes a theory.
A theory is an explanation of a natural phenomenon that is supported by a large body of scientific evidence obtained from many different investigations and observations.
Results and conclusions of investigations are reported in scientific journals, where they are available for examination by other scientists
In addition to theories, scientists also recognize certain facts of nature, called laws or principles that are generally known to be true.
Summary - The Scientific Method
- Was the hypothesis supported by the data?
- Was it not supported?
- Are more data needed?
After results of an investigation have been published, other scientists can try to verify the results by repeating the procedure.
When a hypothesis is supported by data from additional investigations, it is considered valid and is generally accepted by the scientific community.
In science, a hypothesis that is supported by many separate observations and investigations, usually over a long period of time, becomes a theory.
A theory is an explanation of a natural phenomenon that is supported by a large body of scientific evidence obtained from many different investigations and observations.
Results and conclusions of investigations are reported in scientific journals, where they are available for examination by other scientists
In addition to theories, scientists also recognize certain facts of nature, called laws or principles that are generally known to be true.
Summary - The Scientific Method
- Purpose/Observing - What do you want to learn?
- Research - Find out as much about the topic as you can. •Hypothesis - Predict the answer to the problem.
- Experiment - design a test to confirm or disprove you hypothesis.
- Analysis - Record what happened during the experiment
- Conclusion - Was your hypothesis correct?