Lecture III: Scientific Method Flashcards
Two types of scientific investigation
- Discovery Based Science
2. Hypothesis Testing
Discovery Based Science is
- Observing and describing what you see: observation of life, no preconceived ideas, collection and analysis of data.
- Make a general statement based on lots of specific observations
Hypothesis Testing is
- Answer ‘why’ questions by conducting experiments: Test a specific idea (hypothesis) to help answer the ‘why’ question, perform scientific experiments, part of the scientific method
- From general observations and/or studying past research ask specific ‘why’ questions about the living world
Steps of the scientific method
- Observation
- Ask a ‘why’ question
- Formulate a hypothesis
- Make a prediction
- Tests your prediction
- Analyze and interpret results
- Formulate conclusions
Observation is to
- Conduct discovery-based science on your own to collect new observations about a topic of interest.
- Learn about other research that has been done in the past about this topic.
- As scientists we build on the knowledge that has already been attained, test its validity and push to understand further.
Ask a ‘why’ question is to
don’t overthink it
Choose one observation that you would like to understand further and ask a why question.
A hypothesis is
An educated guess based on observations to answer the ‘why’ question.
Hypothesis is denoted by
‘H’ with a subscript if there are more than 1
you cannot prove that your hypothesis is ____, but you can prove that it is ____.
right, wrong
You cannot ____ your hypothesis, you can only _____ it
prove, support
Making a prediction predicts
the outcome of an experiment
Experiments need 3 types of variables
- The Independent variable
- The Dependent variable
- Controlled variables
The independent variable is
The variable that is being manipulated in the experiment
The experimental group should
determine whether the independent variable has the effect that you expected according to your hypothesis.
The control group will provide
a base for comparison with the experimental group(s).
The control groups will rule out
any other variables during the experiment as a possible cause for the results obtained.
Ideally the control group should experience the _____ conditions as the _____ group(s) except for the _____ variable that is being manipulated.
same, experimental, independent
The dependent variable is
The variable that is measured in the experiment
Controlled variables are
Variables that you will keep the same for both the experimental and control groups
Experimental design steps
- Define the hypothesis you are testing
- Define what the null hypothesis is
- Design a controlled experiment that could be repeated by someone else
The null hypothesis is
The null hypothesis is the default position that the manipulation of the independent variable has no effect on the dependent variable
Important things to keep in mind during the experimental design
- Stay objective when performing your experiment and analysing your data.
- Make sure you have a large enough sample size to better represent what is happening in the real world.
- Make sure your experiment is repeatable.
The sample size is
the number of organisms (or independent units of organisms) you have in your experimental and control groups.
Formulating conclusions is deciding
Based on your statistical results, to determine whether you can reject the null hypothesis for your experiment.
