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The Modern Scientific Method
Transcript of The Modern Scientific Method
It focuses on the formulation of hypotheses that can be rejected.
no hypothesis can ever be completely proved, but it can be disproved or rejected
(Popper and Medawar).Often it can be adapted and modified so that it gradually converges more and more closely to the truth.
“A scientist is a searcher after truth, but complete certainty is beyond his reach” (Medawar)
Four sequential phases:
Applied to a task iteratively and recursively to achieve the objective of the task.
Even the simplest tasks often require several attempts to achieve the objective.
Reach over to pick up a glass of lemonade
Surface covered with a thin film of condensation (slippery)
You change your tactics for holding it
Once you grasp it, you try to lift it and it is stuck to the table, you change your tactics again
As you lift it, you observe that it is very full and reduce the speed of movement to your mouth…
Each iteration incurs an additional cost in both time and money.
The vast majority of research and development tasks are unsuccessful. It is important to find out as quickly as possible whether a task is likely to be successful or not.
It's objective is to gain a thorough understanding of the components of the problem domain, leading to the formulation of a single specific and reasonable task objective.
Subject and Idea
Come up with a research subject
Generate the idea that will be studied
help solve problems
How do you come up with an idea?
Example: You hear on the news that biodiesel is the fuel for the future and that many people use leftover oil to produce it. A few weeks later you learn in class that microalgae metabolism may be deviated towards the production of lipids (fats).
Describe the problem
Visit to the Doctor
What seems to be the
I have a ________
I’m just not feeling very well
Regardless of the precision of the answer, you have characterized your problem with a complaint.
You can also answer with your own question or requirement.
What is this rash on my arm?
Please find out what’s causing these terrible headaches!
All these will lead to a Diagnosis
The doctor will explore the background of your problem by asking you how long you have been symptomatic, what have you been eating, what you have been doing, where you have been, what medications you have been taking, etc.
By repeatedly asking the question "Why" (five is a good rule of thumb), you can peel away the layers of symptoms which can lead to the root cause of a problem.
You are on your way home from work and your car stops in the middle of the road.
Why did your car stop?
Because it ran out of gas.
Why did it run out of gas?
Because I didn't buy any gas on my way to work.
Why didn't you buy any gas this morning?
Because I didn't have any money.
Why didn't you have any money?
Because I lost it all last night in a poker game.
Why did you lose your money in last night's poker game?
Because I'm not very good at "bluffing" when I don't have a good hand.
leads to a statement (root cause) that one can take action upon.
is expressed as an interrogative sentence, a declarative sentence, or an imperative sentence that summarizes a question, complaint, or requirement.
Customers complain that the battery in the portable drill (Part #156A-90) loses its charge very quickly when it is not being used.
My dog has fleas
Design a more effective and reliable windshield wiper
Land a team of astronauts on the Moon and bring them safely back
How well can humans recognize the characters on license plates when the surfaces of the plates are severely degraded by dirt or debris?
Why are red and green used for traffic lights to indicate “stop” and “go”, respectively?
Justify research and analyze viability
Evaluate deficiencies of problem knowledge
Relationship between variable
Problem should be measurable or observable
Aims: What it aspires to accomplish (guides the study)
Research question: The what, must be clear.
Justify: Reasons why the study is necessary and/or important (why and for what?)
Viability: resources availability, study's outreach, consequences.
Deficiencies: state of knowledge, new perspectives to study
To justify your investigation think about:
Social relevance (benefits)
Practical implications (real life)
Theoretical value (will any void in research be filled?)
Methodological usefulness (new research tools)
If we use the biodiesel/microalgae example:
: What it aspires to accomplish (guides the study)
: The what, must be clear.
: Reasons why the study is necessary and/or important (why and for what?)
: resources availability, study's outreach, consequences.
: state of knowledge, new perspectives to study
Investigate Related Work
Once the problem has been fully described one may begin the process of finding out as much as possible about what has been done to address the problem and achieve similar objectives in the past.
A review of the literature may reveal that the task objective has already been achieved, and the results of that past project may simply be acquired and applied to the current project.
Perform literature searches of the relevant publications, either in print libraries or at sites on the Internet.
Professional studies and investigations
Internet reports and databases
Newspaper and magazine reports
Not all of these sources and acquisition methods for information are recommended (theft, interrogation, industrial espionage, etc.). Some of them raise clear ethical and legal questions. But make no mistake: all of them are used every day.
Regardless of the source, care must be taken to determine the validity of the information.
Developing a Theoretical Background
Detect any pending (unavailable) literature
Obtain and consult pending literature
Extract and gather important information
Build theoretical background
Prevent errors (somebody else made them before you)
Helps formulate hypothesis
Gives a reference background
Build theoretical background organized by branches (index) or maps (themes and authors, key words)
Literature review (selective)
References must be:
During college: 15-25
Bachelor Thesis: 25-35
Theoretical Background is used:
Learn more about problem
Learn about methods applied to similar problems
Best data collection methods
Refine proposal and suggest hypothesis
Explain differences and similarities between our results and available data
Place our data within existent knowledge
Construct a theory and explanations
Develop new questions and hypothesis.
APA Citation: Series of criteria ranging from
font size and type, to citing style.
What information would be relevant for the theorical background in the biodiesel/microalgae example?
From the Greek hupotithenai meaning
“to suppose or to speculate”
Thus, the fundamental process of hypothesis is
to “speculate” about an underlying cause-effect relationship.
The word “synthesis” derives from the Greek word
to combine separate elements to form a whole”
assemble and test something.
The objective of the Synthesis Phase is
to implement the task method
(solution and experiments) to
the goals and
the hypotheses of the task.
From the latin
It refers to the
capacity of knowledge to resist challenge or attack
The objective is
to decide whether the objective of the task has been achieved,
based on formal conclusions about its goals and hypotheses and a rigorous peer review of the task methodology.
Defining the Scope of Research
Depends on aim.
• Investigate problems not usually researched (many doubts, haven’t been addressed before)
• Innovative perspective
• Id promising concepts (learn about new things)
• Prepares the field for new research
• Riskier because we can’t predict outcome.
Example a new disease, catastrophes in a place where no such thing had ever occurred, human cloning.
Considers the phenomenon under research and its components (specify properties, characteristics, etc.)
Define variables (but doesn’t indicate a relationship)
Shows specific aspects of phenomena, communities, situations, etc.
Explains relationships between variables (positive or negative)
Generate a sense of understanding
Any design may contain elements of one or more of these Scopes.
Explanatory Descriptive, Correlative, or Explanatory.
Descriptive Correlative Explanatory.
What determines how we start our research?
State of knowledge
(the one we wish to give the study)
Support in proving theories
Tentative explanations about relationships between two or more variables.
A variable is property which may change and the variation is measurable or observable. (HERNANDEZ, 2011, p. 93)
According to scope
You may have a hypothesis before completing your theoretical background.
There may be more than 1 (H1, H2, etc.)
Proven or disproven.
Many types only the research hypothesis is stated and used.
Relate to real situation
Variables and terms must be comprehensible, precise and complete
Variables must be defined conceptually and operationally
Relationship between variables must be clear and real
Terms and variables, as well as their relationships must be observable and measurable
Must relate to available techniques in order to be proven
Plan or strategy developed to obtain the information required in an investigation.
Must have control groups.
Usually presence/absence of variable is used
Subgroup of population
Used to later extrapolate findings
You should run a test to see if your method will work before starting your definitive try.
Collect quantitative data with an measuring instrument (reliable, valid, objective)
Data will be measured later with a statistical analysis program
Instruments can be tests (questionnaires, devices, etc.)
Computer programs like:
Once data has been analyzed you need to establish the relationships your data has showed, conclude and discuss your work in the context of other published information. Defend your findings and explain the possible reason(s) for the differences and similarities.
Quantify relationships between variables
Partially explains phenomena (other factors involved)
Risk of false correlations (Kids 8-12, IQ, + correlation height/IQ?)