Experimentation Flashcards
What is a pilot study?
Short experiment that are commonly carried out before starting a scientific investigation
What is the purpose of a pilot study?
To develop and improve experimental protocols, ensuring the experimental design is suitable for investigation the aim
Give advantages of pilot studies
- Allows a new protocol to be developed
- Ensures an appropriate range of values for the independent variable
- Allows practice of an established protocol
What are the three type of variables?
Independent, Dependent, Confounding
What is an independent variable?
Variable that is deliberately manipulation by the investigator to determine if it has an effect on the outcome of the experiment
What is a dependent variable?
Variable that is measured to determine if changing the independent variable has an effect
What is a confounding variable?
Variable, other than the independent variable that may affect the dependent variable
What is used if confounding variables cannot be controlled effectively?
Randomised Block Design
What type of sampling is Randomised Block Design?
Stratified Sampling
What are the two classes of variables?
Discrete
Continuous
What are discrete variables?
Finite values that allow placement into groups
Give an example of a discrete characteristic
Sex
What are continuous variables?
Values that change gradually from one extreme to another
Give examples of qualitative data
Colour of leaf
Emotions
How is qualitative data presented?
Bar graph
Give examples of quantitative data
Time
Height
What are the three types of data?
Quantitative
Qualitative
Ranked
How is quantitative data presented?
Line graph/histogram
How is ranked data presented
Bar graph
What is a multi factorial experiment?
An experiment that is changing more than one independent variable
Give an example of a multi factorial experiment
Field Studies
What are some advantages of simple experiments?
- Simpler experimental design
- Variables are tightly controlled
- Results are easy to analyse
What are some disadvantages of simple experiments?
- Not suitable for testing complex hypothesis
- Difficult to extrapolate
What are some advantages in multi factorial experiments?
- Allows examinations of complex interactions
- Allows generalizations to be made
- Results applicable to whole enviroments
What are some disadvantages of multi factorial experiments?
- More complex and time consuming
- Difficult to control all variables
- Analysis of data is complicated
Define ‘Precision’
Closeness of repeated measurements to one another
Define ‘Accuracy’
Measure of how close the data is to actual true value
Define ‘Validity’
Whether conclusions drawn from a set of results are credible
Define ‘Reliability’
Whether a procedure yields consistent results each time repeated
What is a isotonic solution?
Same osmotic pressure
Free movement of solutions/water
What is a hypertonic solution?
Greater concentration of solution outside
What is a hypotonic solution?
Greater concentration of solution inside
