For An Experiment To Produce Useful Data What Must Happen? The 127 Latest Answer

Experiment

treatment

factor

A factor is a general type or category of treatments. Different treatments represent different levels of a factor. For example, three different groups of runners are subjected to different training methods. The runners are the experimental units, the training methods, the treatments, with the three types of training methods representing three levels of the training type factor.

(Definition from Valerie J. Easton and John H. McColl’s Statistics Glossary v1.1)

Experimental design

The specific questions that the experiment is intended to answer must be clearly identified before the experiment is carried out. We should also try to identify known or expected sources of variability in the experimental units, since one of the main goals of a designed experiment is to reduce the impact of these sources of variability on the responses to questions of interest. That is, we design the experiment to improve the accuracy of our answers.

(Definition from Valerie J. Easton and John H. McColl’s Statistics Glossary v1.1)

control

The problem with this experiment is that the farmer failed to control for the effects of differences in irrigation. This leads to experimental bias, the favoring of certain results over others. To avoid this bias, the farmer should have tested the new fertilizer under identical conditions as the control group that had not received the treatment. Without controlling for external variables, the farmer cannot conclude that it was the effect of the fertilizer and not the irrigation system that produced a better crop.

Another type of bias that is most evident in medical experiments is the placebo effect. Because many patients are confident that a treatment will affect them positively, they respond to a control treatment that actually has no physical effect at all, such as B. a sugar pill. For this reason, it is important to include control or placebo groups in medical experiments to assess the difference between the placebo effect and the actual effect of the treatment.

The mere existence of placebo groups is sometimes not enough to avoid bias in experiments. If members of the placebo group know (or suspect) that they are not receiving actual treatment, the effect of the treatment cannot be accurately assessed. For this reason, double-blind experiments are generally preferable. In this case, neither the experimenters nor the subjects are aware of the group status of the subjects. This eliminates the possibility that the experimenters will treat the placebo group differently than the treatment group, further reducing experimental bias.

randomization

Fully randomized design

Randomized block design

example

A researcher conducts a study on the effectiveness of four different skin creams for treating a specific skin condition. He has 80 subjects and plans to split them into 4 treatment groups of 20 subjects each. Using a randomized block design, subjects will be assessed and placed into blocks of four based on the severity of their skin condition; the four most severe cases are the first block, the next four most severe cases are the second block, and so on up to the twentieth block. The four members of each block are then randomly assigned to one each of the four treatment groups.

(Example from Valerie J. Easton and John H. McColl’s Statistics Glossary v1.1)

Reproduce

Experiments are used to investigate causal relationships. You manipulate one or more independent variables and measure their effect on one or more dependent variables.

Experimental design means creating a set of procedures to systematically test a hypothesis. A good experimental design requires a strong understanding of the system you are studying.

There are five important steps in designing an experiment:

Look at your variables and their relationship. Write a specific, testable hypothesis. Design experimental treatments to manipulate your independent variable. Assign subjects to groups, either between subjects or within subjects. Plan how you will measure your dependent variable

In addition, to draw valid conclusions, you must select a representative sample and control for any extraneous variables that might affect your results. If random assignment of participants to control and treatment groups is impossible, unethical, or very difficult, consider an observational study instead.

Step 1: Define your variables

You should start with a specific research question. We will work with two example research questions, one from health sciences and one from ecology:

Sample Question 1: Phone Use and Sleep You want to know how phone use before bed affects sleep patterns. In particular, you ask how the number of minutes a person uses their phone before sleeping affects the number of hours they sleep.

Sample Question 2: Temperature and Soil Respiration You want to know how temperature affects soil respiration. In particular, you ask how increased air temperature near the soil surface affects the amount of carbon dioxide (CO2) that is respired from the soil.

To translate your research question into an experimental hypothesis, you need to define the main variables and make predictions about how they are related.

Start by simply listing the independent and dependent variables.

Research question Independent variable Dependent variable Phone use and sleep Minutes of phone use before bedtime Hours of sleep per night Temperature and soil respiration Air temperature just above soil surface CO2 respired from soil

Then you need to think about possible extraneous and confounding variables and how to control for them in your experiment.

Extraneous variable How to control phone use and sleep Statistical Control: Measure the mean difference between phone-using sleep and phone-using sleep, rather than the mean amount of sleep per treatment group. Temperature and Soil Respiration Soil moisture also affects respiration, and moisture can decrease as temperature rises. Control experimentally: monitor soil moisture and add water to ensure soil moisture is the same in all treatment plots.

Finally, you can put these variables together in a chart. Use arrows to show the possible relationships between variables and add signs to show the expected direction of the relationships.

Here we predict that the amount of phone use has a negative impact on sleep duration and predict an unknown impact of natural variations on sleep duration.

Here we predict that increasing temperature will increase soil respiration and decrease soil moisture, while decreasing soil moisture will result in decreased soil respiration.

Step 2: Write down your hypothesis

Now that you have a strong conceptual understanding of the system you are studying, you should be able to formulate a specific, testable hypothesis that answers your research question.

Null Hypothesis (H 0 ) Alternative Hypothesis (H 1 ) Phone Use and Sleep Phone use before bed does not correlate with the amount of sleep a person gets. Increasing phone use before sleep leads to a decrease in sleep. Temperature and soil respiration Air temperature does not correlate with soil respiration. Increased air temperature leads to increased soil respiration.

The next steps describe how to design a controlled experiment. In a controlled experiment you must be able to:

Manipulate the independent variable(s) systematically and precisely.

Accurately measure the dependent variable(s).

Control for any potential confounding variables.

If your study system does not meet these criteria, there are other types of research that you can use to answer your research question.

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Step 3: Design your experimental treatments

How you manipulate the independent variable can affect the external validity of the experiment—that is, the extent to which the results can be generalized and applied to the wider world.

First, you may need to decide how much you want to vary your independent variable.

Soil Warming Experiment You can increase the air temperature: just above the natural range for your study region.

over a wider temperature range to mimic future warming.

over an extreme range that is beyond any possible natural variation.

Second, you may need to choose how finely you want to vary your independent variable. Sometimes your experimental system will make that choice for you, but often you have to make a choice, and this affects how much you can conclude from your results.

Phone Usage Experiment You can treat phone usage as: a categorical variable: either binary (yes/no) or as levels of a factor (no phone usage, low phone usage, high phone usage).

a continuous variable (minutes of phone usage measured each night).

Step 4: Assign your subjects to treatment groups

How you apply your experimental treatments to your test subjects is critical to obtaining valid and reliable results.

First, you need to consider the study size: how many people will be involved in the experiment? In general, the more subjects you include, the greater the statistical power of your experiment, which determines how much confidence you can have in your results.

You then need to randomly assign your subjects to treatment groups. Each group receives a different level of treatment (eg, no phone use, low phone use, high phone use).

You should also include a control group that will not receive any treatment. The control group tells us what would have happened to your test subjects without experimental intervention.

When assigning your topics to groups, you have two main decisions to make:

A fully randomized design versus a randomized block design. A between-subjects design vs. within-subjects design.

randomization

An experiment can be fully randomized or randomized within blocks (also called strata):

In a fully randomized design, each subject will be randomly assigned to a treatment group.

each subject is randomly assigned to a treatment group. In a randomized block design (also known as a stratified random design), subjects are first grouped based on a common characteristic and then randomly assigned to treatments within those groups.

Fully randomized design Randomized block design Phone use and sleep All subjects are randomly assigned a level of phone use using a random number generator. Subjects are first grouped by age, and then phone use treatments are randomly assigned within those groups. Temperature and soil respiration Heating treatments are randomly assigned to soil plots using a number generator to generate map coordinates within the study area. Soils are first grouped by average rainfall, and then treatment plots are randomly assigned within those groups.

Sometimes randomization is neither practical nor ethical, so researchers create partially random or even non-random designs. An experimental design in which treatments are not randomly assigned is called a quasi-experimental design.

Between Subjects vs. Inner Subjects

In a between-subjects design (also known as an independent measures design or classic ANOVA design), individuals receive only one of the possible levels of experimental treatment.

In medical or social research, you can also use matched pairs in your between-subjects design to ensure that each treatment group contains the same variety of test subjects in the same proportions.

In a within-subjects design (also known as a repeated measures design), each subject receives each of the experimental treatments in turn, and their responses to each treatment are measured.

Within-subjects or repeated measures can also refer to an experimental design in which an effect occurs over time and individual responses are measured over time to measure that effect as it occurs.

Counterbalancing (randomizing or reversing the order of treatments between subjects) is often used in intra-subject designs to ensure that the order of treatment application does not affect the results of the experiment.

Between-subjects design (independent measures) Within-subjects design (repeated measures) Phone use and sleep Subjects are randomly assigned a level of phone use (none, low, or high) and track this level of phone use throughout the experiment. Subjects are sequentially assigned to no, low, and high phone use throughout the experiment, and the order in which they follow these treatments is randomized. Temperature and Soil Respiration Heating treatments are randomly assigned to soil plots and soils are maintained at this temperature throughout the experiment. Each plot receives each heating treatment (1, 3, 5, 8, and 10 °C above ambient temperature) sequentially throughout the experiment, and the order in which they receive these treatments is random.

Step 5: Measure your dependent variable

Finally, you must decide how to collect data on the outcomes of your dependent variable. You should aim for reliable and valid measurements that minimize bias or error.

Some variables, like temperature, can be objectively measured with scientific instruments. Others may need to be operationalized to turn them into measurable observations.

Phone Use Experiment In your phone use and sleep experiment, you could measure your dependent variable in two ways: Ask participants to record when they go to bed and wake up each day.

Ask participants to wear a sleep tracker.

How precisely you measure your dependent variable also affects the type of statistical analysis you can use on your data.

Experiments are always contextual, and good experimental design takes into account all of the unique considerations of your study system to produce information that is both valid and relevant to your research question.

Frequently asked questions about experiments

Section 2: Experimental Studies

Unlike a descriptive study, an experiment is a study in which a treatment, procedure, or program is intentionally introduced and an outcome or outcome observed. The American Heritage Dictionary of the English Language defines an experiment as “a test, under controlled conditions, conducted to demonstrate a known truth, to test the validity of a hypothesis, or to determine the efficacy of something previously untried.”

Real experiments have four elements: manipulation, control, random assignment, and random selection. The most important of these elements are manipulation and control. Manipulation means that the researcher deliberately changes something in the environment. The control is used to prevent external factors from influencing the study outcome. When something is manipulated and controlled, and then the result occurs, it makes us more confident that the manipulation “caused” the result. Furthermore, experiments involve highly controlled and systematic procedures to minimize errors and biases, which also increases our confidence that the manipulation “causes” the result.

Another key element of a real experiment is random assignment. Random assignment means that if there are groups or treatments in the experiment, participants are assigned to those groups or treatments or randomly (like tossing a coin).

That is, whoever the participant is has an equal chance of being included in all groups or treatments of an experiment. This process helps ensure that the groups or treatments are similar at the start of the study, so there is more confidence that the manipulation (group or treatment) “caused” the outcome. For more information about random assignment, see the Random assignment section.

Definition: An experiment is a study in which a treatment, procedure, or program is intentionally introduced and an outcome or outcome is observed.

Case study for experimental study

Experimental Studies – Example 1

An investigator wants to evaluate whether a new technique for teaching math to elementary school students is more effective than the standard teaching method. Using an experimental design, the investigator randomly (randomly) divides the class into two groups and names them “Group A” and “Group B”. Students cannot choose their own group. The random assignment procedure leads to two groups that should have the same characteristics at the beginning of the experiment. In Group A, the teacher uses a new teaching method to teach the math lesson. In Group B, the teacher uses a standard teaching method to teach the math lesson. At the end of the semester, the examiner compares the test results to assess the success of the new teaching method compared to the standard teaching method. At the end of the study, the results showed that the students in the new teaching group did significantly better on their final exam than the students in the standard teaching group.

Experimental Studies – Example 2

A fitness trainer wants to test the effectiveness of a performance-enhancing herbal supplement on students in her fitness class. In order to form similar experimental groups at the beginning of the course, the students are randomly divided into two groups (they cannot choose which group they are in). The students in both groups are given a pill each day but do not know whether the pill is a placebo (sugar pill) or the herbal preparation. The instructor gives Group A the herbal supplement and Group B gets the placebo (sugar pill). The students’ fitness levels are compared before and after taking the dietary supplement or sugar pill for six weeks. No differences in performance were found between the two groups, suggesting that the herbal supplement was not effective.

Note: The scientific research method is a set of steps generally followed when conducting scientific research. It involves asking questions about a topic, forming a hypothesis about it, designing an experiment to test it, checking whether the results of the experiment agree with the hypothesis or not, and after coming to the conclusion, communicate the result to others scientific world.

Full step-by-step answer:

Whenever a scientist (or generally a person of science) encounters a subject or subject on which he wishes to conduct research, he/she must follow an appropriate sequence of steps known as a scientific principle or scientific research method.

The scientific method involves the following in this proper order.

First, the person needs to gather information and ask questions to learn more about the topic. After studying the information gathered, he formulates a hypothesis (which is a proposed explanation for the subject in question). To test the correctness of the hypothesis, he designs and conducts an experiment. If the results agree with the hypothesis, he continues and draws his conclusion. If not, he changes the hypothesis. After making the conclusions, the person shares their conclusions and results with other people in the scientific world.

Therefore, the correct option is A) Ask questions, make a hypothesis, test the hypothesis, analyze the results, draw conclusions, communicate the results.

Note: The scientific method does not need to be memorized but must be properly understood by reading the explanation above. The scientific method is actually very logical and intuitive when properly understood and thought through.

If the student gets the whole process of the principle right, instead of ambushing it, it will help him a lot not only from the exam standpoint, but in many everyday problems even in everyday life.

What is the scientific method?

The scientific method is an experimental process used to examine observations and answer questions.

Do all scientists strictly follow the scientific method? no Some areas of science are easier to test than others. For example, scientists studying how stars change with age or how dinosaurs digest their food cannot fast-forward the life of a star by a million years or conduct medical studies of how dinosaurs are fed to test their hypotheses. When direct experimentation is not possible, scientists modify the scientific method. But even when modified, the goal (and many of the steps) remains the same: to discover cause-and-effect relationships by asking questions, carefully collecting and examining the evidence, and checking that all available information is combined into a logical answer can become. New information or thoughts can also prompt a scientist to repeat and repeat steps at each point during the process. Understanding the steps of the scientific method will help you focus your scientific question and work through your observations and data to answer the question as best you can.

The interactive diagram below can help you understand the scientific method and how it is applied to an experiment. You can click parts of the chart to learn more. Use the “Back to Top” button to return to the chart for more information.

Diagram of the scientific method. The scientific method begins with a question, and background research is conducted to try to answer that question. If you want to find evidence for an answer or an answer yourself, construct a hypothesis and test that hypothesis in an experiment. If the experiment works and the data is analyzed, you can either prove or disprove your hypothesis. If your hypothesis is disproved, you can go back with the newfound information and create a new hypothesis to start the scientific process over.

Steps of the scientific method

1. Ask a Question The scientific method begins with you asking a question about something you are observing: how, what, when, who, what, why, or where? For a science fair project, some teachers require the question to be something you can measure, preferably with a number. Your question

Lab Notebook For detailed help on this step, use these resources:

2. Conduct background research Instead of starting from scratch to put together a plan to answer your question, you want to be an accomplished scientist, using libraries and internet research to help you figure out the best course of action and make sure you don’t repeat past mistakes. background research plan

find information

How to write an APA and MLA style bibliography with examples

Research Paper For detailed help on this step, use these resources:

3. Make a hypothesis A hypothesis is an educated guess about how things work. It’s an attempt to answer your question with an explanation that can be tested. With a good hypothesis, you can then make a prediction:

“If _____[I do] _____, then _____[this]_____ will happen.” State both your hypothesis and the resulting prediction that you will test. Forecasts must be easily measurable. variables

Variables for Beginners

Writing a Hypothesis for Your Science Fair Project Use these resources for detailed help with this step:

4. Test your hypothesis with an experiment Your experiment tests whether your prediction is correct and therefore supports your hypothesis or not. It is important that your experiment is a fair test. You conduct a fair test by making sure you only change one factor at a time, while keeping all other conditions the same. You should also repeat your experiments several times to ensure that the first results are not accidental. test execution

material list

Running an Experiment For detailed help on this step, use these resources:

5. Analyze your data and draw a conclusion Once your experiment is complete, collect your measurements and analyze them to see if they support your hypothesis or not. Scientists often find that their predictions were not accurate and their hypothesis was not supported, and in such cases they share the results of their experiment and then go back and construct a new hypothesis and prediction based on the information they found during their experiment have learned. This starts much of the process of the scientific method all over again. Even if they find that their hypothesis has been confirmed, they might want to test it again in a new way. Data Analysis & Graphics

Conclusion Use these resources for detailed help on this step:

6. Communicate your findings To complete your science fair project, share your findings with others in a final report and/or display board. Professional scientists do almost exactly the same thing, publishing their final report in a scientific journal or presenting their findings on a poster or during a presentation at a scientific meeting. At a science fair, the judges are interested in your findings, whether or not they support your original hypothesis. final report

abstract

scoreboard

Science Fair Judging Use these resources for detailed help with this step:

Helpful video explaining the scientific method

The Scientific Method: Steps and Examples https://www.youtube.com/watch?v=Xxm_beTs2LU

frequently asked Questions

What are the six steps of the scientific method?

The six steps of the scientific method include: 1) asking a question about something you are observing, 2) doing background research to learn what is already known about the subject, 3) constructing a hypothesis, 4) experimenting to test the hypothesis to test, 5) analyze the data from the experiment and draw conclusions, and 6) share the results with others.

What is a scientific method example?

Ask a Question: Why does Greenland look so big on a map?

Why does Greenland look so big on a map? Background research: Learn that Greenland is a quarter of the landmass of the United States. Also learn that Mercator projection maps are created by transferring the images from a sphere onto a sheet of paper wrapped around the sphere in a cylinder.

Learn that Greenland is a quarter of the landmass of the United States. Also learn that Mercator projection maps are created by transferring the images from a sphere onto a sheet of paper wrapped around the sphere in a cylinder. Hypothesis: When I create a Mercator projection map, the objects in the center of the map look their true size and the objects at the poles look larger than they really are.

When I create a Mercator projection map, the objects in the center of the map look their true size and the objects at the poles look larger than they really are. Experiment: Use a sphere with 1 inch by 1 inch squares at each pole and equator to create a Mercator projection map. Measure the squares on the Mercator projection map.

Use a sphere with 1 inch by 1 inch squares at each pole and equator to create a Mercator projection map. Measure the squares on the Mercator projection map. Analyze data and draw conclusions: the squares at the center of the map average 1 inch per side, while the squares at the poles average 3 inches per side. In summary, the projection process used to create Mercator projection maps produces distortions at the poles but not at the equator. That’s why Greenland, which is near the North Pole, looks bigger than it is.

The squares in the center of the map average 1 inch per side, while the squares at the poles average 3 inches per side. In summary, the projection process used to create Mercator projection maps produces distortions at the poles but not at the equator. That’s why Greenland, which is near the North Pole, looks bigger than it is. Communicate: Make a video, write a report, or give a presentation to educate others about the experiment. A simple example of the scientific method is:

Who invented the scientific method?

The scientific method was not invented by a single person, but is the result of centuries of debate about how best to discover how the natural world works. The ancient Greek philosopher Aristotle was among the first known people to advocate the use of observation and reasoning to understand how nature works. The Arab Muslim mathematician and scientist Hasan Ibn al-Haytham (known in the western world as Alhazen) is often cited as the first to write about the importance of experimentation. Since then, a multitude of scientists have written about how science should ideally be done, contributing to our modern understanding of scientific method. These scientists include Roger Bacon, Thomas Aquinas, Galileo Galilei, Francis Bacon, Isaac Newton, John Hume, and John Stuart Mill. Today’s scientists continue to develop and refine the scientific method as they explore new techniques and new fields of science.

Do scientists actually use the scientific method?

Scientists use the scientific method, but not always exactly as outlined in the organized steps taught in the classroom. Just as a chef can make a few changes to a recipe based on the ingredients present, a scientist can modify the scientific method by skipping steps, jumping back and forth between steps, or repeating a subset of steps because he or she happens to be doing it does with imperfect real conditions. But scientists always strive to adhere to the core principles of scientific method, using observation, experiment, and data to support or reject explanations for how a phenomenon works. While experiments are considered the best way to test explanations, there are areas of science like astronomy where this is not always possible.

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Which of the following methods breaks down organic matter and recycles the nutrients back to the earth?

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A laboratory study aims to determine whether the hormone thyroxine increases metabolic activity in rats. Twenty rats of the same species, age and weight are selected and divided into two equal groups. All other factors in the study remain the same except that one group received distilled water while the other group received distilled water with thyroxine.

The variable studied in this experiment is the…