Methodology of Scientific Investigations Learning Objectives:
After studying this material you should be able to:
1. Outline the general process of science including the critical steps of the scientific
method.
1.
2.
3.
4.
5.
6.
7.
Observation
Question
Hypothesis
Investigative Design
Prediction
Data Collection
Data Analysis & Conclusions
2. Identify the steps of the scientific method from a description of scientific research.
Scientific research involves a more circular process to the scientific method than a
linear one. For example, if the data collected does not support the hypothesis, the
investigator should circle back to the central question and write a new hypothesis. If
the data supports the hypothesis, the investigator should find new experiments to
investigate. Scientific research also includes writing reports. The reports include the
following elements: Title, Abstract, Introduction, Methods, Results, Discussion,
Citation.
1.
2.
3.
4.
Observation
Question: central question
Hypothesis: answers the central question, can be testable, can be falsifiable.
Investigative Design: experimental investigation or observational
investigation, the experiment should be reproducible.
5. Prediction: relates to the investigation and predicts the results.
6. Data Collection
7. Data Analysis & Conclusions: categorical or continuous, discuss the results
and their relevance, find ways to improve experiment or find new experiments
to support hypothesis.
3. Formulate a central question based on observations.
The central question is based on observations and is the basis of the hypothesis.
Example: I made an observation that my cat was losing weight. A central question
would be: Is the cat food type not providing enough nutrients?
4. In proper format, formulate a hypothesis to answer a central question.
A hypothesis is an answer to the central question based on prior knowledge. It should
be testable and can be rejected or supported after data is collected. Example: Grian
free cat food Is the most nutrient type cat food.
5. In proper format, formulate a prediction about expected results based on a previouslyestablished hypothesis.
Predicts the results of the experiment if the hypothesis is correct. It will be an “if,
then” statement. Example: If the cat gains more weight when consuming grain free
cat food, then it is the most nutrient type of cat food.
6. Design an investigation to answer a central question appropriately defining and
identifying: all variables (independent, dependent, controlled/constant); the
experimental treatment; the control treatment; and the methods/materials needed to
collect appropriate data.
Variables:
Independent: controlled by the investigator. Ex: type of cat food.
Dependent: measured by the investigator and depends in the independent
variables. Ex: cat’s weight.
Control: variables remain constant. Ex: times cat food is served to the cat, amount
of water available.
Treatment:
Experimental: modified based on the independent variable chosen. Example:
changing the type of cat food.
Control: Independent variable is unchanged. condition to which experimental
treatment can be compared.
- Negative control: no results. Ex: using the original brand of cat food
- Positive control: best results. Ex: using the best brand of cat food on
the market.
Data:
Continuous: measured data that doesn’t fall into categories, has infinite numbers.
Use line graphs or scatter plots.
Categorical: data falls into categories. Use bar graphs.
7. Analyze collected data and formulate conclusions to determine if actual and predicted
results correlate or not and if a hypothesis is supported or contradicted.
Data either rejects or supports the hypothesis. If the hypothesis is contradicted, then
we should go back to the central question and identify a different hypothesis. If the
hypothesis is supported, we can identify different experiments to continue supporting
our hypothesis. Compare the results to the predict results. Identify the relevancy of
the data and state any new questions that arise from the data.
8. Compare and contrast an experimental investigation with an observational
investigation identifying the similarities and differences.
Experimental investigation: occurs in a controlled setting such as a lab, looking for
something specific, measurable outcomes.
Observational investigation: Occurs in nature with uncontrolled settings such as a
park, looking for patterns and trends.
Both: have a hypothesis, prediction, independent , dependent & control variable,
control and experimental treatment, data collection and analysis.