Experimentation P.1 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
Give advantages of pilot studies (3)
- 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?
An independent variable is the variable that is changed in a scientific experiment.(x-axis variable)
What is a dependent variable?
A dependent variable is the variable being measured in a scientific experiment. (y-axis variable)
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 (falling into distinct groups).
2. Continuous (having a range of values)
Give 2 examples of qualitative data (i.e characteristics or qualities)
- Emotions
2. Colour of leaf
How is qualitative (characteristics/qualities) data presented?
Bar graph
What is a multi factorial experiment?
Experiments that combine more than one independent variable or treatment
What is an Advantage and disadvantage of multifactorial experiment (3)
- More generalisable than simple experiments because it’s using several different independent factors
- Results are more applicable to an in vivo situation.
- But they are more complex to perform and analyse
What is an Advantage and disadvantage of simple experiment (2)
- they are straightforward to perform (due to the ease of controlling laboratory conditions)
- but their results may not be applicable to an in vivo situation.
What is Precision?
Precision measures how closely grouped the measured values are to each other
How is Validity achieved?
by having variables controlled so that any measured effect is likely to be due to the independent variable.
How is reliability achieved?
By having consistent values in repeats and independent replicates.
What is a hypertonic solution?
A solution that contains more dissolved particles (such as salt and other electrolytes) than is found in normal cells and blood.
What is a hypotonic solution?
A solution that contains fewer dissolved particles (such as salt and other electrolytes) than is found in normal cells and blood.
What is isotonic solution?
A solution that contains same concentration of dissolved particles (such as salt and other electrolytes) as found in normal cells and blood
What are the types of sampling?
- Systematic
- Stratified
- Random
What is systematic sampling?
Members of pollution selected at regular intervals
What is random sampling?
Members of population having equal chance of being selected
What is stratified sampling?
Population divided into categories and sampled proportionally
What is in vitro experiment?
Carried out using isolated parts of an organism in the lab.
What is in vivo experiment?
Carried out within whole living organism.
Advantage and disadvantage of in vivo?
While in vivo are more realistic of natural conditions they are less easy to control/replicate
