Things I forget 2.0

Question 1

What are the 3 Rs in animal studies?

Answer 1

• replacement
• reduction
• refinement

Question 2

Define the 3 Rs in animal studies?

Answer 2

• Replacement
  
  • methods which avoid or replace the use of animals
• reduction
  
  • fewer animals being used
• refinement
  
  • minimise pain and distress and increase animal welfare

Question 3

How must scientific research be justified and risk assessed?

Answer 3

• value of scientific investigations must be justifiable in terms of the benefits of its outcome, including the pursuit of scientific knowledge
• as a result of risks involved, many areas of scientific research are highly regulated and licensed by governments

Question 4

What must be taken into account when conducting scientific research?

Answer 4

the risk to and safety of:
- subject species
- individuals
- investigators
- the environment

Question 5

What other factors can influence scientific research?

Answer 5

legislation
regulation
policy
funding

Question 6

What is the effect of legislation on scientific research?

Answer 6

it limits the potential for the misuse of studies and data

Question 7

What is the definition of validity?

Answer 7

variables controlled so that any measured effect is likely to be due to the independent variable

Question 8

What is the definition of reliability?

Answer 8

consistent values in repeats and independent replicates

Question 9

What is the definition of accuracy?

Answer 9

data, or means of data sets, are close to the true value

Question 10

What is the definition of precision?

Answer 10

measured values are close to each other

Question 11

What is a pilot study used for?

Answer 11

• it is integral to the development of an investigation
  used to help:
• plan procedures
• asses validity
• check techniques

Question 12

What are the benefits of carrying out a pilot study?

Answer 12

• allows evaluation and modification of experimental design
• can ensure an appropriate range of values for the independent variable
• be able to establish the number of repeat measurements required to give a representative value for each independent datum point

Question 13

Explain observational studies and correlation and causation

Answer 13

• good at detecting correlation, but since they do not directly test a hypothesis
• they are less useful for determining causation

Question 14

Explain how to carry out a randomised block design

Answer 14

Randomised blocks of treatment and control groups can 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.

Question 15

What is the role of a negative control?

Answer 15

it provides results in the absence of a treatment

Question 16

What is the role of a positive control?

Answer 16

a treatment that is included to check that the system can detect a positive result when it occurs

Question 17

What is the placebo effect?

Answer 17

a measurable change in the dependent variable as a result of the patients expectations, rather then the changes in the independent variable

Question 18

What is a placebo?

Answer 18

included as a treatment without the presence of the independent variable being investigated

Question 19

When is a larger sample size required?

Answer 19

more variable populations

Question 20

What should a representative sample have?

Answer 20

it should share the same mean and the same degree of variation about the mean as the population as a whole

Question 21

What are the 3 types of sampling?

Answer 21

random
systematic
stratified

Question 22

What is stratified sampling?

Answer 22

the population is divided into categories that are then sampled proportionately

Question 23

What may variation in experimental results be caused by?

Answer 23

• reliability of measurement methods
• and / or inherent variation in the specimens

Question 24

Why should independent replication be carried out?

Answer 24

to produce independent data sets

Question 25

When can overall results only be considered reliable?

Answer 25

if they can be achieved constantly

Question 26

What should happen to independent data sets and why?

Answer 26

- they should be compared - to determine the reliability of results

Question 27

What is qualitative data?

Answer 27

subjective and descriptive

Question 28

What is quantitive data?

Answer 28

can be measured objectively. usually with a numerical value

Question 29

What is ranked data?

Answer 29

the data transformation in which numerical values are replaced by their rank when the data are sorted from lowest to highest

Question 30

How do you calculate median?

Answer 30

- order values from lowest to highest - find the middle value - if there are two middle values, then add them together and divide by two to find the middle value

Question 31

How do you calculate mode?

Answer 31

- order numbers from either lowest to highest or highest to lowest - count how many tines each number appears in the set - the one that appears most is the mode - there can be more than one mode, or no mode

Question 32

How do you find the lower quartile, upper quartile and interquartile range

Answer 32

- find the median - find the median of the first half of the data (Q1) - find the median of the second half of the data (Q3) - find the difference between Q3 and Q1 (Q3-Q1)

Question 33

What are box plots used for?

Answer 33

to show variation within and between data sets

Question 34

What is an error bar?

Answer 34

a line through a point on a graph, parallel to one of the axes, which represents the uncertainty or variation of the corresponding coordinate of the point

Question 35

What is the difference between correlation and causation?

Answer 35

correlation is an association and does not imply causation

Question 36

When does causation exist?

Answer 36

if the changes in the values of the independent variable are known to cause changes to the value of the dependent variable

Question 37

When does a positive correlation exist?

Answer 37

an increase in one variable is accompanied by an increase in the other variable

Question 38

When does a negative correlation exist?

Answer 38

when an increase in one variable is accompanies by a decrease in the other variable

Question 39

Explain strong and weak correlations

Answer 39

strength of correlation is proportional to spread of values from line of best fit

Question 40

What should a method section contain?

Answer 40

sufficient information to allow another investigator to repeat the work

Question 41

What should the experimental design address and why?

Answer 41

the intended aim and the hypothesis the validity and reliability of the experimental design should be evaluated an experimental design that does not address the intended aim or hypothesis is invalid

Question 42

When may the validity of an experiment be compromised?

Answer 42

when factors other than the independent variable influence the value of the dependent variable

Question 43

What is selection bias?

Answer 43

the selection of a sample in a non-random way, so that the sample is not representative of the whole population

Question 44

What may prevent a representative sample being selected?

Answer 44

selection bias

Question 45

When may it be impossible to avoid selection bias?

Answer 45

sample size may not be sufficient to decide without bias whether the change to the independent variable has caused an effect in the dependent variable

Question 46

How do you determine weather the differences between means are likely or unlikely to have occurred by chance?

Answer 46

statistical tests

Question 47

What is a statistically significant result?

Answer 47

one that is unlikely to be due to chance alone

Question 48

What do error bars indicate?

Answer 48

the variability of data around a mean

Question 49

What indicates that the difference may have been significant?

Answer 49

if the treatment mean differs from the control mean sufficiently for their error bars not to overlap

Question 50

What should conclusions refer to?

Answer 50

- the aim, the results and the hypothesis - the validity and reliability of the experimental design should be taken into account - consideration should be given as to weather the results can be attributed to correlation or causation

Question 51

What should evaluation of conclusions refer to?

Answer 51

existing knowledge and the results of other investigations