The Scientific Method

Prelab

Thoroughly explore the website “Understanding Science: How Science Really Works” at

http://undsci.berkeley.edu. Answer the following seven questions in your lab notebook based

on your exploration of this website. Your answers must illustrate to me that you have actually

read the information in the website. You will not get full credit for this prelab if you answer

the questions based on what you learned already in high school without reading the material

in the website. You will be expected to show me your answers to these questions at the

beginning of lab.

1. Based on your exploration of the website “Understanding Science: How Science Really Works”

describe what science is in 3-4 sentences.

2. Is the following statement true or false and why is it true or false: science is only a collection of

facts?

3. Based on your exploration of this website describe in a paragraph or series of bulleted steps

how science is practiced.

4. Describe in a paragraph or series of bulleted steps how you may use your knowledge of the

process of science to evaluate news reports and statements.

5. Is the following statement true or false and why is it true or false: science is the best method for

investigating the super natural?

6. Based on your exploration of this website describe in a paragraph who a scientist is.

7. Briefly describe at least two ideas you previously held about science that exploring this website

has caused you to reconsider.

Procedure

Your professor will explain the “cube puzzle” to you. Please participate in and enjoy this

activity.

You’ve “solved” the cube puzzle and explored the website “Understanding Science: How

Science Really Works”.

Form a group of 2 students (in other words pick a lab partner) and record your names on the

lines below.

______________________________________________________________________________

______________________________________________________________________________

Read the essay titled The Scientific Method found near the end of this lab write up. Also

examine the five diagrams illustrating the scientific method found near the end of this lab write

up. Then answer the following six questions. If you and your lab partner do not agree please

make sure both person’s thoughts are included in your answer.

1. Do all of the diagrams agree?

2. How are the diagrams similar and how do they differ? Consider the steps involved and

the order of these steps. Please record your answer in the space provided below.

3. Please list the steps you believe are important in practicing science and the order of or

relationship between the steps you listed. Please explain your answer. Consider your

experience with solving the cube puzzle as well as information you gained from your

reading and exploration of the website.

4. How would you have defined the word theory before having taken this course?

5. How do you define the word theory now?

6. What is the difference between a hypothesis and a theory?

Webster’s New World dictionary defines the word reason as “to think logically; draw inferences

or conclusions from facts known or assumed; to think out systematically; analyze…” Webster’s

New World dictionary defines the word objective as “having to do with a known object as

distinguished from something existing only in the mind; real, actual, regarded as something

independent of the mind; without bias or prejudice, detached; reality …”, and the word

subjective as “resulting from the feelings of the person thinking; determined by and

emphasizing the ideas, thoughts, feelings; not rigidly reflecting reality; having to do the

perception or conception of a thing by the mind as opposed its reality independent of the

minds; incapable of being checked externally or independently by other persons …”

Discuss the following questions with your lab partner and record your conclusions in the space

provided below. Both of these questions are heatedly debated and there is not one correct

answer to either question. If you and your lab partner do not agree please make sure both

person’s thoughts are included in your answer.

1. There are many fields of science. These fields are frequently divided into categories

such as the social sciences – including sociology, psychology, political science and

education, and the natural sciences – including biology, chemistry, physics and geology.

Is there a definable scientific method and should there be a ridged scientific method

practiced in all of the fields of science and why or why not?

2. Is the scientific method objective or subjective reasoning? Explain your answer.

Scientific Observations An essential skill for any scientist is the ability to make detailed, reliable observations. Good observations lead us to ask the “how” and “why” questions of scientific investigation. In other words scientists cannot form hypothesis without having made good observations. As a guide, observations may contain the following elements: Quantitative observation – uses measuring devices or instruments and records numerical

measurements. All Quantitative observations must include the unit of measurement as well as the numerical value of the measurement.

Qualitative observation – records what your senses perceive. In your description you may use comparisons. Use words “as” and “like”, e.g., “The anole is green like grass.” “The leaf feels like sand paper.”

Sense of sight. What does the object look like? Describe its appearance. Provide minute details. Look for something new every time you make an observation.

Sense of smell. What does the object smell like? What odors does it have? How would you describe them?

Sense of touch. What does it feel like? Rough, slippery, smooth? Be specific. Don't speak in generalities.

Sense of sound. What sounds does it make? Have you listened many times a day to make sure you are capturing variations in sound over time?

Action. Describe the action, such as, “When I place a strong acid on the substance gas bubbles are given off.”

Sketch. Provide a detailed sketch of all or part of whatever you are observing.

In this brief activity, you will practice scientific observation by making five different, detailed observations about the items shown to you by your instructor. Be careful to record exactly what you observed and only what you observed. Do not to record inferences or assumptions about these items. Item 1: 1. __________________________________________________________________ 2. __________________________________________________________________ 3. __________________________________________________________________ 4. __________________________________________________________________ 5. __________________________________________________________________ Item 2: 1. __________________________________________________________________ 2. __________________________________________________________________ 3. __________________________________________________________________ 4. __________________________________________________________________ 5. __________________________________________________________________

Work with another set of lab partners to form a group of 4 students. Each pair of lab partners should examine the observations made by the other pair of lab partners in their group of 4. Look for any bias, inaccuracies, conclusions, inferences or assumption in the observations previously made by the other pair of lab partners in your group of 4. Record any biases, etc. you see in the spaces provided below. Item 1: 1. __________________________________________________________________ 2. __________________________________________________________________ 3. __________________________________________________________________ 4. __________________________________________________________________ 5. __________________________________________________________________ Item 2: 1. __________________________________________________________________ 2. __________________________________________________________________ 3. __________________________________________________________________ 4. __________________________________________________________________ 5. __________________________________________________________________ In what other ways could you make observations of these items besides the methods you used above?

Which type of observation do you think is most likely to be biased quantitative or qualitative

and why?

How does what you’ve observed so far in this course concerning the scientific method compare

to what you learned in high school and/or in previous college courses? Your answer should

illustrate to me that you have read the requested material and thought about these readings

and about your experiences so far. Please record your answer in the space provided below.

The Scientific Method

There are many fields of science. The fields of science are often categorized as either social science,

such as sociology, psychology, or political science, or natural science, such as biology, chemistry,

geology, and physics. The practice of each of these sciences is a complex process and differs somewhat

from field to field. The practice of science is often called the scientific method.

Making Observations

The first step in practicing many of the natural sciences is making observations. In science it is important

to make careful observations and record all observations in detail. Observations may be qualitative or

quantitative. Quantitative observations involve numerical values and generally result from

measurements. Qualitative observations are recording what you can physically sense. It is often not

possible to sense chemical changes or phenomena. Chemical phenomena are often detected and

measured using sophisticated instruments. Measurements always involve a numerical value and a unit

of measurement. Being able to make and manipulate measurements is necessary in science. It is

seldom possible to know what phenomena or details are important in advance. Part of the point of

making observations is to determine what is unusual. Therefore, it is important to record what you see,

smell, hear, otherwise sense, or measure that is not expected as well as what is expected. It is better to

record irrelevant details than to miss details. Recorded irrelevant details may be ignored later. Missed

observations cannot necessarily be repeated and may cause an incorrect hypothesis to be formed or

cause the phenomena of interest not to be understood at all. It is necessary to record all details

because you will not remember them if you do not record them. Your results will be viewed later by

other scientists who will not know about any unrecorded observations. Also reviewing recorded

observations at a later time may spark ideas that may not occur to you otherwise. The practice of

science is a long term process. Observations are generally made over an extended period of time by

more than one scientist before hypotheses are formed.

Review the observations you have made before you leave the laboratory to ensure (1) you have

considered all comparative information and (2) your observations have not been contaminated by

assumption, expectations or belief. When you place a strong acid on an egg white you see the color

change from clear to opaque white. This is an observation. If you record that the egg cooked, you have

contaminated your observation with a belief that the white color was caused by the egg being cooked.

Ask yourself what led you to conclude that the egg was cooked in order to see what observations you

actually made. Allowing expectations or beliefs to impact your observations may lead to incorrect

hypotheses and/or an inability to understand the phenomena under study.

Forming Hypotheses

Forming a hypothesis is often the second step in the natural sciences. A hypothesis is based on previous

observations made yourself or by other scientists and therefore a hypothesis cannot be formed without

a set of reliable and detailed observations and a thorough literature review. A hypothesis is a possible

explanation for the observations that have been made. Forming a hypothesis is a creative process. If

the hypothesis is not new and unique it is not useful. In forming a hypothesis trends in observations or

data and relationships between observations or data are examined and causes and effects are explored.

Hypothesis must be testable by an experiment(s). The hypothesis must be clearly stated so that it can

be proven true or false by an experiment(s). In other words the difference between a true and false

outcome must be clearly stated in the hypothesis. A hypothesis should be stated so that it can be

answered with either yes (true) or no (false). For example whether or not the quality of Mars Hill tap

water is good is not a hypothesis. It cannot be answered yes or no. Mars Hill tap water is of good

quality is a statement that can be answered with yes or no. However, it is not a clearly stated testable

hypothesis because more details are need concerning what the word good means. Mars Hill tap water

meets all Environmental Protection Agency standards for tap water in the US is a testable hypothesis.

Designing Experiments

The use of experiments is one of the distinguishing features of the natural sciences. Designing an

experiment well is difficult and requires a great deal of knowledge frequently in a variety of fields. Often

a team of scientists work together in forming hypotheses and designing experiments. In most

experiments some property or factor is altered or varied in a controlled manner and the response of

another property or factor is observed or measured and recorded. The factor that is changed, such as

time, is called the independent variable, and the response is called the dependent variable, because the

response is influenced by or dependent on the changing variable. When the data produced is presented

as a graph, the independent variable is generally the horizontal or x-axis and the dependent variable is

generally the vertical or y-axis. In a well designed experiment only one factor is varied at a time. If more

than one factor is allowed to vary at the same time it is not possible to draw verifiable conclusions

concerning the cause of the response observed. In some experiments it is necessary to use a control in

order to only change one variable at a time. Here two identical populations, such as mice, are used in

the experiment. Both populations are treated identically with the exception of one factor that is varied,

such as administering a known amount of a toxic compound, and the responses of both populations are

measured and recorded. The population not given the toxic compound is called the control. When

studying living things it is seldom possible to keep all possible or even the most important variables

constant and a well designed control is almost always needed. In chemistry and physics it is often

possible to keep the important variables constant and a control may not be necessary. In chemistry and

physics identifying all of the important variables is most important. The number of steps in an

experiment should be minimized in order to minimize error.

Sharing Results

Scientists publish their results in peer-reviewed journals and other scientists then try to

duplicate the results. After many scientists have duplicated and verified the results and refined the

hypothesis, the hypothesis may in time be considered a theory. The word theory is often used much

differently by the general public than the word is used by scientists.

Figures taken from the social science literature

Figures taken from the natural science literature

Figures taken from the natural science literature