biology - 3 Flashcards
What does the null hypothesis propose?
That there will be no statistically significant effect as a result of the experiment treatment.
When is the null hypothesis rejected?
If there is evidence for an effect, unlikely due to chance.
When do scientific ideas become accepted?
Once they have been checked independently.
What is peer review?
Specialists with expertise in the relevant field assess the scientific quality of a submitted manuscript and make recommendations regarding its suitability for publication.
What do review articles do?
Summarise current knowledge and recent findings in a particular field.
What does the replication of experiments by others reduce?
The opportunity for dishonesty or the deliberate misuse of science.
What is the importance of integrity and honesty given by?
Unbiased presentation of results, citing and providing references, avoiding plagiarism.
In animal studies, what are used to avoid, reduce or minimise the harm to animals?
The concepts of replacement, reduction, and refinement.
What are some human ethics?
Informed consent, the right to withdraw, and confidentiality.
What must the value or quality of science investigations be justifiable in terms of?
The benefits of its outcome, including the pursuit of scientific knowledge.
As a result of the risks involved, what are many areas of scientific research?
Highly regulated and licensed by governments.
What can all influence scientific research?
Legislation, regulation, policy and funding.
What does legislation limit?
The potential for the misuse of studies and data.
What is validity?
Variables controlled so that any measured effect is likely to be due to the independent variable.
What is reliability?
Consistent values in repeats and independent replicates.
What is accuracy?
Data, or means of data sets, are close to the true value.
What is precision?
Measured values are close to each other.
What is a pilot study used for?
To help plan procedures, assess validity and check techniques.
What does the pilot study allow?
Evaluation and modification of experimental design.
It allows the investigator to establish the number of repeat measurements required to give a representative value for each independent datum point.
What can the use of a pilot study ensure?
An appropriate range of values for the independent variable.
What is an independent variable?
The variable that is changed in a scientific experiment.
What is a dependent variable?
The variable being measured in a scientific experiment.
What are multifactorial experimental designs?
A combination of more than one independent variable or combination of treatments.
What is an advantage and a disadvantage of the control of laboratory conditions?
It allows simple experiments to be conducted more easily than in the field. However, a drawback of a simple experiment is that its findings may not be applicable to a wider setting.
In observational studies, what is the independent variable?
Not directly controlled by the investigator, for ethical or logistical reasons.
What are observational studies good at detecting?
Correlation, but since they do not directly test a hypothesis, they are less useful for determining causation.
What are confounding variables?
Other variables besides the independent variable may affect the dependent variable.
In cases where confounding variables cannot easily be controlled, what could be used?
A randomised block design.
How can randomised blocks of treatment and control groups be distributed?
In such a way that the influence of any confounding variable is likely to be the same across the treatment and control groups.
What does the negative control do?
It provides results in the absence of a treatment.
What is a positive control?
A treatment that is included to check that the system can detect a positive result when it occurs
What is the placebo effect?
A measurable change in the dependent variable as a result of a patient’s expectations, rather than changes in the independent variable.
What does in vitro refer to?
The technique of performing a given procedure in a controlled environment outside of a living organism.
What does in vivo refer to?
Experimentation using a whole, living organism.
What determines the appropriate sample size?
The extent of the natural variation within a population.
What should a representative sample share?
The same mean and the same degree of variation about the mean as the population as a whole.
What happens in randomised sampling?
Members of the population have an equal chance of being selected.
What happens in systematise sampling?
Members of a population are selected at regular intervals.
What happens in stratified sampling?
The population is divided into categories that are then sampled proportionally.
What may variation in experimental results be due to?
The reliability of measurement methods and/or inherent variation in the specimens.
How could the reliability of measuring instruments or procedures be determined?
By repeated measurements or readings of an individual datum point.
What should be carried out to produce independent data sets?
Independent replication.
What do discrete and continuous variables give rise to?
Qualitative, quantitative, or ranked data.
What do error bars indicate?
The variability of data around a mean.
