Experimentation

Describe the scientific cycle

Observation; construction of a testable hypothesis; experimental design; gathering, recording, and analysis of data; evaluation of results, and conclusions; the formation of a revised hypothesis where necessary

What are the 3 R’s and what are they used for?

Replacement, reduction and refinement to avoid, reduce or minimise the harm to animals

What is validity?

The control of variables so that any measured effect is due to the independent variable

What is reliability?

Consistent values in repeats and independent replicates

What is accuracy?

Data or means of data sets that are close to the true value

What is precision?

Measured values that are close to eachother

What is In vitro techniques?

Experimental procedure carried out in a controlled environment outside a living organism

What is In vivo techniques?

Experimentation using a whole living organism

What are the advantages and disadvantages of In vivo studies?

Advantage - they stimulate real life and chronic effects can be tested

Disadvantage - they are difficult to control, slow, expensive and may have ethical issues

What are the advantages and disadvantages of In vitro studies?

Advantages - they are controllable, repeatable, rapid, cheap and may avoid eithical issues

Disadvantages - Extrapolition to who organism or natural ecosystems is difficult and chronic effects are not tested

What is a representative sample?

A sample that sahres the same mean and same degree of variation about the means as the population as a whole

What occurs in random sampling?

Members of the population have an equal chance of being selected

What occurs in stratified sampling?

The population is divided into categories that are sampled proportionally

What occurs in systematic sampling?

Members of a population are selected at regular intervals