Unit 3 - Investigative Biology Flashcards
Name the stages of the scientific cycle
Observation; build a hypothesis; experimental design; gathering recording and analysis of data; evaluation of results and conclusions; revising hypothesis where necessary
What is a null hypothesis?
It propeses there will be no statistically significant effect as a result of the experimental treatment
Name common methods of sharing original scientific findings
Seminars, talks, posters at conferences and publishing in academic journals
What does peer review mean?
When specialists with expertise in the relevant field assess the scientific quality of submitted research and make reccomendations on its suitabilty for publication
What are review articles?
They summarise current knowledge and recent findings in a paticular field
What are the 3 Rs used in animal studies?
Replacement, reduction and refinement
What ethics are involved in human studies?
Informed consent, right to withdraw and confidentiality
How can the reliabilty of an experiment be increased?
Replicating the experiment to reduce the chance for dishonesty or the deliberate missuse of science
Define validity
Variables are controlled so that any measured effect is likely to be due to independent variable
Define reliability
Consistent values in repeats and independent replicates
Define accuracy
Data, or means of data sets, are close to the true value
Define precision
Measured values are close to each other
What is a piloty study used for?
To plan procedures, assess validity and check techniques as well as figure out the number of repeats required to give a representative value
What is an independent and dependent variable?
Independent - variable that is changed
Dependent - variable being measured and observed
What is a drawback of simple experiment?
Findings may not be applicable to a wider setting
What is a multifactorial experiment?
An experiment with a combination of more than one independent variable or combination of treatments
Define confounding variables
Variables beside the independent variable which may affect the dependent variable
What is a randomised block design?
When blocks of treatment and control groups are randomly distributed in such a way that the influence of confounding variables is likely the same across all treatments and control groups
Why are controls used?
Used for comparision with the results of treatment groups
What are negative and positive controls?
Negative - provides results in the absence of treatments
Positive - included to check that the system can detect a positive result
What is placebo effect?
A measurable change in the dependent variable as a result of a patient’s expectations, rather than changes in the independent variable
Define in vitro and in vivo
In vitro - performing a given procedure in a controlled environment outside living organism
In vivo - experiement using whole, living organism
What determines an appropriate sample size?
The extent of natural variation within a population
Describe a representative sample
A representative ample should share the same mean and the same degree of variation about the mean as the population as a whole
Define random sampling
Members of a population have an equal chance of being selected
Define stratified sampling
The population is divided into categories that are then sampled proportionally
Define systematic sampling
Member of a population are selected at regular intervals
How can the reliabilty of measuring instruments or procedures be tested?
Repeated measurements or readings of an individual datum point. The variate observed indicates precision but not neccessarily accuracy
Why should independent replication be carried out?
Overall results can only be considered reliable if they can be achieved consistently
Describe quantative and qualitative data
Quantative - can be measured and given numerical values
Qualitative - subjective and descriptive
Define ranked data
When data recorded is placed into hierarchical order
Define positive and negative correlation
Positive - exists when an increase in one variable is accompanied by an increase in the other
Negative - exists when an increase in one variable leads to a decrease in the other variable
