Scientific Design & Method
Ethical Limits
"Do no harm" lab animals sometimes used instead of humans, controversy on testing of animals & humans, before testing on humans & animals studies are done on cell & tissue cultures
Graph-Bar Graph
2 data points=a bar graph
Causation
A cause and effect relationship in which one variable controls the changes in another variable.
Scientific Design: Designing the Experiment
A good design starts with determining variables. An experiment is a procedure used to create a fair test of a hypothesis. A completely fair test is one that shows no bias or favoritism toward any variable, whether controlled or uncontrolled, within the experiment.
Correlation
A measure of the extent to which two factors vary together, and thus of how well either factor predicts the other. Not the cause.
Hypothesis
A proposed, scientifically testable explanation for an observed phenomenon.
Scientific Investigation
A scientific investigation is the way in which scientist study the natural world. First, you ask a question. Then you figure out a way to find the answer.
Scientific Method: Ask a Question Based on Observation Do Background Research Construct a Hypothesis Test Hypothesis with Experiment Analyze Data & Draw a Conclusion Communicate Results (Publish in a Journal)
A way to ask and answer scientific questions by making observations and doing experiments Scientists use the scientific method to search for cause & effect of relationships in nature. They design an experiment so that changes to one item causes something else to vary in a predictable way
Changing Methods
Change containers, work in natural environment
Scientific Design-Why Evaluate
Design of the experiment has everything to do with the conclusions, bad design=invalid conclusions
Avoiding Bias
Experiment not well controlled, other problems not resolved,samples not randomly chosen, control & experimental groups cannot be selective, subjects must be randomly chosen
Replicating
Repeating an experiment to determine whether the findings are reliable, Must be able to be replicated
Statistical inferences
The act or procedure of using statistics from a sample to learn about parameters in a population
Data analysis
The process of compiling, analyzing, and interpreting the results of primary and secondary data results
Spallanzini
proved digestion in the stomach is the result of chemical reactions Responsible for conducting experimenst using flasks of broth - it showed that organisms in the air could cause growth of bacteria
Experimental group
In an experiment, the group that IS exposed to the treatment; contrasts with the control group and serves as a comparison for evaluating the effect of the treatment.
Control group
In an experiment, the group that is not exposed to the treatment; contrasts with the experimental group and serves as a comparison for evaluating the effect of the treatment.
Overcoming Limits
Limit scope of study, do many smaller studies over a longer period, acknowledge the limitations
Scientific model
Makes it easier to understand things that are too difficult to observe directly (too large, too small, dangerous)
Scientific practices & values promote the development of scientific knowledge
New data changes scientific knowledge, change occurs when repetition leads to acceptance, forming & testing hypotheses, evaluating, generating new questions & hypotheses
Graph-Not a usable graph
On a graph 1 data point is not useful
Limits to Scientific Design
Time, money, available equipment, other practical concerns
Emperical evidence
data collected directly by observation or through experimentation
Scientific Knowledge
knowledge obtained through systematic, comprehensive, coherent, clear, and consistent methods.
Natural variables
light, temp, pH, CO2, nutrients
Graph-Line Graph
many data points=line graph, gives validity to data
Changing timing
time measured on a graph can be changed, the longer the time the better the data