Scientific Method (updated)

Summary

This video script delves into the essence of science and the scientific method, emphasizing its objectivity and self-correcting nature. It distinguishes science from non-scientific practices like fortune-telling and astrology. The script outlines the scientific method's steps, from observation to experimentation, using examples like DNA experiments and sleep studies. It highlights the importance of control and experimental groups, independent and dependent variables, and the iterative process of hypothesis testing and validation. The video also discusses how hypotheses can evolve into theories with sufficient evidence, and the potential for theories to change with new information.

Takeaways

• 🔬 Science is a systematic process that produces information about the natural world, excluding unobservable and untestable phenomena like fortune-telling and astrology.
• 🧐 Science aims to be objective and self-correcting, with biases and flaws ideally identified and corrected through peer review and repeated experimentation.
• 🔄 Science is repeatable, meaning an experiment should yield the same results when conducted under the same conditions to ensure validity.
• 👀 Tools of science include direct observation, such as using microscopes and telescopes, and robotic observations like NASA's Voyager probes.
• 🧬 Experimentation is a core part of science, as illustrated by Frederick Griffith's discovery of genetic transfer between bacteria through his transformation experiment.
• 🤔 The scientific method involves a series of steps: identifying a problem, forming a hypothesis, designing and conducting an experiment, analyzing data, drawing conclusions, and repeating the process for verification.
• 📊 In experiments, the control group receives no special treatment and serves as a comparison to the experimental group, which has one differing factor known as the independent variable.
• 🛌 An example experiment showed that soft calming music might enhance sleep quality, as measured by an increase in average hours slept when the independent variable (music) was introduced.
• 📈 Data from experiments, known as the dependent variable, can be analyzed and visualized using graphs and tables to compare outcomes between groups.
• 🔄 The scientific method is self-correcting; if data does not support a hypothesis, the hypothesis is revised, and the process is repeated.
• 🌐 Over time, repeated confirmation of hypotheses can lead to the development of scientific theories, which are well-substantiated explanations that are subject to change with new information.

Q & A

What is the definition of science according to the script?

Science is the process that produces information about the natural world, emphasizing the study of natural phenomena and excluding practices like fortune-telling, card reading, palm reading, and zodiac readings, which are not considered scientific due to their lack of observability and testability.

Why is science considered self-correcting?

Science is self-correcting because it is a shared process; when biases or flaws in an idea are identified by others, they are scrutinized and corrected, ensuring the integrity and accuracy of scientific findings.

What are the key characteristics of a scientific experiment?

A scientific experiment should be objective, repeatable, and based on observable and testable phenomena. It often involves direct observation, robotic observations, and experimentation to gather data and information.

What is the significance of the scientific method in conducting experiments?

The scientific method is a series of steps used to collect information and solve problems. It involves identifying a problem, forming a hypothesis, designing and conducting an experiment, collecting and analyzing data, drawing conclusions, and repeating the process to confirm results or refine hypotheses.

What is the role of the control group in an experiment?

The control group serves as a baseline for comparison in an experiment. It receives no special treatment and is used to measure the effect of the independent variable by comparing its outcomes to those of the experimental group.

Can you explain the difference between an independent variable and a dependent variable?

The independent variable is the factor being tested or manipulated in an experiment, while the dependent variable is the outcome or data measured as a result of changes to the independent variable.

What is the purpose of repeating an experiment in the scientific method?

Repeating an experiment ensures the reliability of the results, confirming that the findings are not due to chance and are consistent under the same conditions.

How does a hypothesis differ from a theory in the context of science?

A hypothesis is a tentative explanation proposed to explain a phenomenon, while a theory is a well-substantiated explanation that has been repeatedly tested and confirmed through observation and experimentation over time.

What does it mean for an experiment to be 'fair' or 'valid' in scientific terms?

A fair or valid experiment is one that isolates the independent variable to ensure that any observed effects can be attributed solely to it. It controls for other variables that could potentially influence the outcome and confound the results.

Why is it important to maintain a single independent variable in an experiment?

Maintaining a single independent variable is crucial to ensure that the experiment's conclusions are clear and not confounded by multiple factors. It allows for a definitive determination of cause and effect.

How does the script illustrate the process of testing a hypothesis?

The script uses the example of a young lady who hypothesizes that listening to soft calming music improves her sleep. She conducts an experiment with a control and experimental group, collects data on sleep duration, analyzes the data, and draws a conclusion based on whether the hypothesis is supported or rejected by the data.

Outlines

00:00

🔬 Introduction to Science and the Scientific Method

The script introduces the concept of science as a systematic process for understanding the natural world, distinguishing it from non-scientific practices like fortune-telling and astrology. It emphasizes the importance of objectivity, repeatability, and the self-correcting nature of science. The tools of science are explored, including direct observation, robotic observations like NASA's Voyager missions, and experimentation, exemplified by Isaac Newton's apple story and Frederick Griffith's bacterial transformation experiment, which demonstrated the transfer of genetic information.

05:02

🔍 The Scientific Method: Steps and Hypothesis Testing

This paragraph delves into the steps of the scientific method, starting with identifying a problem or making an observation, followed by formulating a hypothesis—a tentative explanation. The method involves designing and conducting experiments, collecting and analyzing data, and drawing conclusions. The self-correcting aspect of science is highlighted through the process of repeating experiments to verify results. A practical example is given involving a young lady who tests the hypothesis that soft calming music improves sleep quality, using a control and experimental group, and employing a fitness tracker to measure sleep duration.

10:04

📊 Data Analysis and Conclusions in Scientific Experiments

The script explains the process of data analysis in scientific experiments, using the sleep study example to illustrate how data from control and experimental groups is compared. The importance of the dependent variable, which is measured during the experiment, is discussed, as well as how graphs can be used to visualize data. The conclusion of the experiment is derived from the data, distinguishing between raw data and the main idea or conclusion. The paragraph also touches on the evolution of hypotheses into theories over time, with Charles Darwin's theory of natural selection as an example, and the potential for new information to update scientific understanding.

15:05

🎯 Identifying Variables in Scientific Scenarios

This section presents several scenarios to practice identifying control and experimental groups, as well as independent and dependent variables within scientific experiments. Examples include a military sleep study, a farmer's fertilizer test, a student's study method comparison, and a city's investigation into the effects of air pollution on physical fitness. The scenarios are designed to reinforce the understanding of experimental design and the role of variables in drawing scientific conclusions.

20:08

🚫 The Importance of Fairness in Scientific Experiments

The final paragraph addresses the concept of fairness in scientific experiments, using a modified sleep study scenario as an example where multiple variables are changed simultaneously. It explains why such an experiment would be considered unfair or invalid because it would be impossible to determine which variable is responsible for the observed results. The paragraph reinforces the need for single-variable manipulation in experiments to ensure that conclusions are clear and attributable to the independent variable being tested.

Keywords

💡Science

Science is the systematic study of the natural world through observation and experimentation. It is the process that produces knowledge and understanding of natural phenomena. In the video, science is contrasted with non-scientific practices like fortune-telling and astrology to emphasize its empirical and testable nature. The script highlights that science is objective, self-correcting, and repeatable, which are fundamental to its methodology.

💡Scientific Method

The scientific method is a structured procedure for conducting scientific investigations, consisting of steps such as identifying a problem, forming a hypothesis, designing and conducting an experiment, analyzing data, and drawing conclusions. The video script describes the scientific method as a self-correcting process that involves sharing and peer review to ensure the accuracy and validity of scientific claims.

💡Hypothesis

A hypothesis is a tentative explanation or prediction made to address a scientific problem or question. It is a testable proposition that serves as a starting point for an experiment. In the script, the concept is exemplified by the young lady who hypothesizes that soft calming music improves her sleep, which is then tested through an experiment.

💡Experiment

An experiment is a controlled procedure carried out to validate or refute a hypothesis. It involves manipulating variables and observing the effects to test scientific theories. The video script provides examples of experiments, such as the DNA experiment by Frederick Griffith and the sleep study involving soft calming music, to illustrate how experiments lead to the collection of data and the drawing of conclusions.

💡Observation

Observation is the act of gathering information through the senses or with the aid of scientific instruments. It is a fundamental part of science, as it provides the initial data that leads to questions and hypotheses. The script mentions direct observation, such as using a microscope or telescope, and the famous anecdote about Isaac Newton being inspired by observing a falling apple.

💡Control Group

A control group is a standard part of an experiment that does not receive the experimental treatment, serving as a baseline for comparison with the group that does receive the treatment. In the script, the control group is used in various scenarios, such as the sleep study and the military marksmanship test, to demonstrate the importance of having a comparison group for valid scientific conclusions.

💡Experimental Group

The experimental group is the part of an experiment that receives the treatment or intervention being tested. It is compared against the control group to determine the effect of the independent variable. The script discusses the setup of the experimental group in the sleep study, where the subject listens to soft calming music, contrasting it with the control group's normal conditions.

💡Independent Variable

The independent variable is the element in an experiment that the researcher manipulates to test its effect on the dependent variable. It is the factor that is intentionally changed to observe its impact on the outcome. In the script, the independent variable in the sleep study is the presence of soft calming music, which is varied to see its effect on sleep quality.

💡Dependent Variable

The dependent variable is the outcome or response measured in an experiment, which is expected to change as a result of the manipulation of the independent variable. It is 'dependent' on the independent variable in the sense that its value is influenced by changes to that variable. The script uses the amount of sleep recorded by a fitness tracker as the dependent variable in the sleep study example.

💡Data Analysis

Data analysis involves examining and interpreting the results of an experiment to draw conclusions. It often includes creating graphs and tables to visualize the data. The script describes how the data from the control and experimental groups in the sleep study is analyzed and compared, using a bar graph to illustrate the difference in sleep duration with and without music.

💡Theory

A theory in science is a well-substantiated explanation of some aspect of the natural world, based on a body of facts that have been repeatedly confirmed through observation and experimentation. The script mentions Charles Darwin's theory of natural selection as an example of a hypothesis that, over time and through rigorous testing, has become an accepted scientific theory.

Highlights

Science is a process that produces information about the natural world, excluding unobservable and untestable phenomena like fortune-telling and horoscopes.

Science is objective and self-correcting, with biases and flaws being identified and corrected over time through peer review and repetition.

Science is repeatable, requiring experiments to be consistent and withstand scrutiny to validate claims.

Direct observation, such as using microscopes or telescopes, is a fundamental tool in gathering scientific information.

Robotic observations, like NASA's Voyager probes, extend our ability to observe and collect data from beyond our solar system.

Experimentation, exemplified by Frederick Griffith's discovery of genetic transfer in bacteria, is key to advancing scientific knowledge.

The scientific method involves a series of steps starting with identifying a problem, forming a hypothesis, and designing an experiment.

Hypotheses in science are tentative explanations that can be tested and potentially lead to the formation of theories.

Experiments should have a control group for comparison and an experimental group where the independent variable is manipulated.

The independent variable is the factor being tested in an experiment, while the dependent variable is the measured outcome.

Data analysis involves comparing control and experimental groups, often visualized through graphs and tables.

A conclusion in science is the main idea learned from an experiment, distinguishing it from the raw data collected.

The scientific method concludes with the possibility of repeating experiments to ensure the reliability of results.

Hypotheses and theories can evolve with new information, as demonstrated by shifts in understanding of the Earth's position and shape.

Charles Darwin's theory of natural selection started as a hypothesis and became an accepted scientific theory through repeated confirmation.

Fairness in experiments is crucial, ensuring that only one independent variable is changed to avoid confounding results.

Practice scenarios and problems help solidify understanding of the scientific method and its application in various contexts.

Transcripts

okay so today's topic is science and the

scientific method so let's go ahead and

get started well first of all you know

what is science well it's the process

that produces information about the

natural world and I do want to stress

the word the phrase there the natural

world you know natural phenomenon so

therefore things like you know

fortune-telling and you know reading

cards to predict your future is not a

science nor is palm reading and you know

you wouldn't know that by driving around

the streets of Los Angeles there's a lot

of these businesses in operation but you

know none of these are considered

scientific and neither is you know

zodiac readings you know your horoscope

and and and you know trying to live your

life by astrological signals and symbols

so these while they might be

entertaining to some are definitely not

within the realm of science they're not

observable they're not testable so what

is then science well we number one we

try to be objective of course that's

very very difficult I mean we're humans

we are dealing with human flaws and we

all have biases that might inadvertently

shape our opinions and our ideas and but

the great thing about science is that it

is self-correcting because as we go

through the scientific method science is

shared with others and then if there are

biases and flaws in an idea they are

hopefully identified by others and

scrutinized and therefore then self

correct science is repeatable I mean if

you're doing an experiment and you have

this outrageous claim that your product

you know changes the world in some

revolutionary way that has to be

repeatable and you know therefore live

up to the scrutiny of science so tools

and skills that we use in in science

number one is simply direct observation

you know in the picture here we have

some folks doing simple microscope

observations and observing the

microscopic world well here we have a

couple people

making a telescope observation you know

looking through a telescope and

observing something in the nighttime sky

and this observation is again

information that that is about the

natural world well also we can do

robotic observations you know 1977 NASA

launched Voyager 1 Voyager tube these

probes have been floating around in the

solar system and now beyond the solar

system since the late 1970s observing

measuring and sending information back

to you know NASA here for observations

and another you know kind of a maybe a

tall tale perhaps that point you know

Isaac Newton gets bonked on the head

with a falling Apple and therefore as a

young lad that helped him uncover the

secrets of gravity you know did that

tall tale actually happen you know I

don't know if we have a good answer to

that but again an observation of falling

objects leading to great leaps of

discovery here and let's not forget you

know another area of science is simply

experimentation you know maybe and like

the young lady in this picture doing DNA

experimentation trying to read the DNA

printout of a DNA molecule you know a

kind of a famous experiment done in 1928

Frederick Griffith Frederick Griffith

excuse me taught us that bacteria can

actually transfer genetic information

now watch when he did he injected these

mice with a harmless bacteria and to no

surprise the mice survived then he took

a deadly strain of the bacteria injected

into the mice and to no surprise the

mice died well then he took the deadly

bacteria but he heated the bacteria the

heat killed the bacteria injected the

dead deadly bacteria into the mice and

no surprise the mice survived well

here's where it got interesting

he took the harmless bacteria that were

very much alive

and mixed them with the dead deadly

bacteria the heated bacteria and by

doing such he was expecting the mice to

survive however they died so in this

experiment he learned that bacteria can

transfer genetic information from one to

another

turns out the harmless bacteria was

transformed into a deadly version of

bacteria because the harmless bacteria

picked up pieces of DNA from the dead

deadly bacteria kind of an interesting

little experiment where we learned a

good deal amount of information and so

data and information is gathered by what

we call the scientific method so let's

go ahead and talk about that so the

scientific method the series of steps to

collect information and solve problems

well it begins with identifying a

problem or making an observation asking

a question something that is curious

you're curious about and you're

wondering the solution when next comes

what you think this solution is you know

a little bit of research and you can

construct a hypothesis a tentative

explanation to your problem and from

there you then design the experiment and

we're gonna go through an example in a

moment and that experiment will lead to

data being collected and then we have to

of course analyze that data from the

data we can of course draw a conclusion

and from our conclusion after our

conclusion we would then repeat and now

here's where it gets kind of interesting

because if our hypothesis appears to be

supported by the analyzed data well then

of course we want to repeat and perform

the experiments again to make sure to

make certain of our results but if our

data indicates that the hypothesis is

not supported well then we have to

reconstruct a hypothesis and kind of

start all over again so this is what I

meant earlier when I said that science

is self-correcting mistakes are

identified and hopefully can therefore

then be corrected

well let's get into testing an idea

again the scientific method begins with

a problem or an observation well last

night where we have a young lady in our

picture she accidentally fell asleep

with her headphones on while listening

to soft calming music she awoke

refreshed and feeling better than she

did on most other days well that's an

observation her observation in this

example might be you know I seem to

sleep better when I play soft calming

music so now she's gonna create a

hypothesis you know our hypothesis is a

proposed explanation a tentative

explanation what she thinks the reason

for her better sleep would be in this

example was the soft calming music now

notice how I worded my hypothesis as an

if-then statement if there is soft

calming music plane then I will sleep

better that would be an example of a

hypothesis okay so now let's go on and

actually perform an experiment well

first thing I want to mention is in an

experiment there are two groups of test

subjects we call the one group the

control group and the other group the

experimental group well let's focus on

what the control group is first so let's

focus on our control group you know this

is the part of the experiment that

receives no special treatment we use the

control group as a comparison we're

going to compare the control group

eventually to the experimental group so

here we have our test subjects sleeping

in a nice warm comfortable environment

and you know during the day she's eating

healthy meals during the day she's doing

proper exercise and she decides you know

what she's gonna measure her amount of

sleep for seven days and she's gonna use

her fitness tracker to record her sleep

you know if you have a Fitbit or a Apple

watch you know a lot of fitness trackers

have tools on them to record how much

and how well you sleep every night so

she's gonna wear a fitness tracker to

record her sleep

well now let's turn our attention to the

experimental group we're gonna set this

up the same as the control group but

with one difference now before we talk

about the difference let's focus on

setting it up as the same as the control

group so our our young lady here is

gonna sleep in a warm comfortable

environment she's gonna have healthy

meals during the day she's gonna perform

regular fitness activities during the

day she's gonna conduct the experimental

group for seven days and she's gonna use

her fitness tracker to record how much

sleep she gets every night but now let's

talk about the one factor we call this

one factor that differs we call it the

independent variable this is the factor

that we are testing and in this case we

are testing whether or not sleep the

soft calming music has an impact on her

ability to sleep every night and so that

would make it the independent variable

so the independent variable is the one

factor that differs between the control

group and the experimental group now

during the experiment remember we're

gonna use our fitness tracker to record

how much she sleeps every night let's

pretend during the cut the seven days of

the control group she averages six and a

half hours of sleep per night and during

the seven days of the experimental group

she averages eight hours of sleep per

night this data that we gathered we call

the data that is measured during the

experiment we call this the dependent

variable and I hope you see why it's

called the dependent variable because

the sleep depended upon the independent

variable the sleep the amount of sleep

depended upon whether or not she was

listening to music that was the

independent variable so in this case the

dependent variable is the amount asleep

that was recorded every night by her

fitness tracker so whatever data you are

measuring in a science experiment that

is the dependent there

well now let's talk about analyzing the

data we already know the control group

and during the control group she

averaged six and a half hours of sleep

per night and during the experimental

group eight hours of sleep per night so

data from the control group is going to

be compared to the experimental group

and we can do that often via by making

tables and graphs and in this case I've

created a graph for you where it's a bar

graph which shows the amount of sleep

during the seven days without music six

and a half hours of sleep and the seven

days of sleep with music eight hours of

sleep per night so you can clearly see

that with the soft calming music plane

she averages more sleep and so graphs

are a great way to visualize your data

and now based on this data we can

determine whether or not our hypothesis

was supported or rejected remember her

earlier hypothesis was if I play soft

calming music through the night then I

will sleep better right now the data

sure seems to support her hypothesis and

so now comes to our conclusion this is

the main idea that we have learned now

let me ask you I'm going to give you two

choices which of these choices would be

the conclusion think of it like a

multiple choice choice one soft calming

music enhances the ability to sleep or

how about this soft calming music

averaged eight hours of sleep versus six

and a half hours when not listening to

music which of these is the conclusion I

hope you realize it's the first one the

second choice that just disappeared

that's not the conclusion that was the

data that you actually gathered there's

a difference between the data gathered

in the main idea that we have learned or

the conclusion and in this case soft

calming music seems to enhance her

ability to sleep that would be a

conclusion so as we wrap up the

scientific method our final step really

is to repeat you know our findings can

be shared and repeated by others you

know to repeat this sleep experiment the

second time a third time would be a

really good idea just to make sure that

our results are true and not due to

chance well as time passes

perhaps with new experimentations and

new observations from other scientists

perhaps hypotheses may grow into what's

called a theory you might recognize the

picture of Charles Darwin here well

today Darwin's idea of natural selection

is an accepted scientific theory but in

1859 when he published his book the

Origin of Species he really started out

as his hypothesis and over the years his

hypothesis has been confirmed

time after time at the time by other

scientists and so today we call natural

selection a theory which means it's a

well substantiated explanation acquired

through the scientific method and

repeatedly tested and confirmed through

observation and experimentation but I do

want to mention that you know hypotheses

and theories can always change based on

new information you know there was a

time when the earth was believed to be

stationary the center of the universe

and not only that but also flat well

that was because of based on the

information we had at a time that

appeared to be most accurate of course

as time passed we eventually learned

that hey the earth is round and it's

really the earth that is in rotation

around throughout the universe so new

information can update hypotheses and

theories

well you know here are the notes before

I want to give you a scenario and then a

few practice problems so in this

scenario the military wants to know of

soldiers with only four hours of sleep

can operate at the same level as those

who normally get seven hours of sleep

100 soldiers are allowed to sleep for

four hours a night and another hundred

are allowed to sleep for seven hours a

night the soldiers are then tested for

marksmanship and the firing range based

on this story I think you should be able

to answer these four questions pause the

video because I'm gonna go over the

answers in three two one so first of all

name the control group in this

experiment or those are the soldiers

with seven hours asleep because the

control group is the group that receives

no special treatment and to get seven

hours of sleep is the normal situation

the next part name the experimental

group of those are the soldiers would

ever receive four hours of sleep because

we're manipulating this experimental

group name the independent variable that

would be the amount of sleep the

definition of the independent variable

it's the fact that we are testing we are

testing seven hours of sleep versus four

hours of sleep and then name the in

excuse me name the dependent variable

well that would be their score on the

firing range their marksmanship because

we can measure that and the data that is

gathered is the dependent variable let's

do another one of these practice

scenarios

okay here's another scenario a farmer

wants to test the new fertilizer for his

crops he sections off two large areas of

his field and in section a he waters his

crops as usual and uses his normal

fertilizer called grow right in Section

B he waters his crops as usual but adds

ever grow fertilizer after one growing

season he records the growth of the

crops based on this story I think you

should be able to answer these four

questions answer the questions and I'm

gonna and pause the video because I'm

gonna go over the answers now in three

two one

so name the control group I hope you

said that's Section A because again the

control group is the part of the

experiment that receives no special

treatment section a gets water as usual

and the normal fertilizer name the

experimental group that's Section B we

are manipulating the the the factors of

section B by giving them a new

fertilizer number three name the

independent variable well that would be

the type of fertilizer again the

independent variable is the factor we

are testing and we're testing the type

of fertilizer and then name the

dependent variable what are we actually

measuring the growth of the crops let's

do another scenario

here we have a student and he wants to

know if his new study method is more

successful than his traditional study

method so for one month he studies for

his classes using his traditional study

method and a next month he studies for

his classes using his new study method

and at the end he compares his grades

well here are the four questions pause

the video try to answer these I'm going

to go over the answers in three two one

so name the control group I hope you

said well that's the one month of

traditional studying name the

experimental group well that's the one

month of this new experimental study

method whatever it may be named

independent variable that's the study

method and name the dependent variable

that data being gathered is the greater

are the grades one more of these

practice problems

okay in this final scenario the city of

Los Angeles wants to know if there is a

connection between physical fitness and

air pollution in Group A the volunteers

ride a stationary bike for one hour in a

pollution-free air timbre in Group B the

volunteers ride a stationary bike for

one hour and a chamber filled with air

pollutants common to Los Angeles and

their heart rates are monitored

throughout the rides well here are the

four questions pause the video try to

answer them I'm gonna go over the

answers in three two one

so name the control group I hope you

said hey that's Group B because again

the control group receives no special

treatment

Group B they are riding a bike in the

chamber filled with air pollutions air

pollutants common to Los Angeles named

the experimental group now I hope you

said that's group a because we're

manipulating this group or removing all

the air pollution whatsoever and so

we're manipulating group a named the

independent variable that would be the

quality of the air and what about the

dependent variable that would be their

heart rates so I hope you get the idea

of how these scenarios work

well let me pose this question to you

would it be fair to do this

remember our sleep experiment would it

be fair let's say we have our warm

comfortable environment in the control

and experimental group and member and

the experimental group our young lady

here is listening to soft calming music

but during the day she's doing different

exercise programs during the day she's

eating different meals she's still gonna

use her fitness tracker to record her

sleep and she's still gonna do this for

a total of seven days is this a fair

experiment and let's pretend she

averages again let's keep the numbers

the same pretend she averages six and a

half hours of sleep per night in the

control group and eight hours of sleep

per night in the experimental group I

hope you realize no this is not a fair

experiment this experiment would not be

viewed as a valid scientific experiment

and I hope you see why if I were to ask

you how many independent variables are

in this experiment I hope you realize

there's three one of them being whether

or not she listens to music another a

second being the exercise program she

performs during the day and a third

being the meals she eats during the day

well why why is this a big deal but I

hope you realize well maybe that extra

amount of sleep was caused by the

calming music but maybe that extra sleep

was caused by the change in exercise

habits but maybe that extra sleep was

caused by the change of the eating

habits and maybe that extra sleep was

caused by a combination of these factors

and that's the point we can't narrow it

down a science experiment is supposed to

allow you to come to a single conclusion

and in this case we just can't do that

there's too many possible explanations

to explain why she averaged more sleep

in the experimental group this

experiment would need to be recreated

okay so as I wrap up this video I want

to thank you for watching you know

here's a little practice quiz for you to

try and if you're in my class I'm happy

to check your answers before or after

school one day thanks for watching