Foundations of Life Sciences: The Scientific Method

A set of vocabulary flashcards covering the objective approach of the scientific method, its seven steps, its limitations, and the core components of experimental design.

Scientific Method

An objective approach to answering questions in Science involving observation, analysis, and experimentation.

Hypothesis

A proposed explanation for a phenomenon, often formulated as an "If/then" statement.

Theory

A substantiated explanation supported by experimentation on several hypotheses that may change as more data becomes available.

Observation (Step $1$)

The process of identifying what is happening of interest to you and your field, such as noting that current antibiotics are no longer effective against Staphylococcus infections.

Ask a Question (Step $2$)

Inquiring about the reasons for observations, such as asking if new antibiotics can be identified to treat Staphylococcus.

Research Current Literature (Step $3$)

Gathering data on known facts and related experiments, such as finding that fungal alkaloids have antibacterial properties.

Formulate a Hypothesis (Step $4$)

Predicting an outcome or explanation based on research, for example: "If Staphylococcus is exposed to fungal extracts, then their growth will be inhibited."

Test the Hypothesis (Step $5$)

Setting up experiments to determine if the predicted outcome occurs, such as exposing Staphylococcus cultures to various fungal compounds.

Measure, Record & Analyze Results (Step $6$)

Arranging data into groups and visual displays like graphing to determine if the results support or refute the hypothesis.

Retest (Step $7$)

Repeating the experiment to ensure results are repeatable, primarily conducted if the hypothesis was supported.

Double-blind Design

An experimental design where neither the experimenter nor the test subjects know who receives what treatment.

Controls

Experimental components providing known situations for comparison of results to ensure proper design.

Positive Control

A known situation where a phenomenon is expected to occur, showing what a positive result looks like.

Negative Control

A known situation where no phenomenon is expected to occur, showing what a negative result looks like.

Variables

Changing conditions within an experiment; includes independent, dependent, and control types.

Independent Variable

The changed condition in an experiment that may cause a change in results, such as a specific fungal compound.

Dependent Variable

The measured outcome of the experiment.

Control Conditions

Conditions that could change but are prevented from changing to limit the independent variable to one.

Control Group

A group of test subjects that receives no treatment or standard treatment and does not have the independent variable applied.

Experimental Group

A group of test subjects that has one specific variable, the independent variable, applied to them.

Replicants

Several copies of each test group used to allow for averaging of results.

Staphylococcus Example Data

Specific results where compounds $F1$, $F6$, and $F8$ displayed inhibitory action at a concentration of $5\text{ }Ιl/ml$.