3.2 Experimental Design

Question 1

What are pilots studies and what do they do?

Answer 1

They are small, preliminary studies which aim to investigate whether crucial components of a main study will be feasible.

Question 2

What are some advantages of pilot studies?

Answer 2

Plan Procedures
Access Vadility
Check tequniques
Evaluation and modification of experimental design

Question 3

What is a Variable?

Answer 3

Any factor that can be controlled or changed or measured in an experiment

Question 4

What is a dependent variable?

Answer 4

The variable being measured in a scientific experiment

Question 5

What is an independent variable?

Answer 5

The thing changed in a scientific experiment.

Question 6

What is continuous variation?

Answer 6

Take on an infinite number of values

Question 7

What is discrete variation?

Answer 7

Have a finite range of values

Question 8

What is the difference between simple and multifunctional experiments?

Answer 8

Multifunctional is more than one variable

Question 9

An observational study is?

Answer 9

When the independent variable is not directly controlled by the investigator for ethical or logistical reasons.

Question 10

What are observational studies good for?

Answer 10

Detecting correlation

Question 11

Why would randomised block design be used?

Answer 11

In cases where confounding variables cannot be easily controlled.

Question 12

What is a positive control?

Answer 12

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

Question 13

What is a negative control?

Answer 13

Provides results in the absence of a treatment.

Question 14

What is a placebo?

Answer 14

Something that can be included as a treatment without the presence of the independent variable being investigated

Question 15

What is a placebo effect?

Answer 15

A measurable change in the dependent variable as a result of a patient’s expectations, rather than changes in the independent variable.

Question 16

What is in vitro?

Answer 16

The technique of performing a given procedure in a controlled environment outside of a living organism.

Question 17

What is in vivo?

Answer 17

Refers to experimentation using a whole, living organism.

Question 18

A representative sample should….

Answer 18

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

Question 19

What is random sampling?

Answer 19

Members of the population have an equal chance of being selected.

Question 20

What is systematic sampling?

Answer 20

Members of a population are selected at regular intervals

Question 21

What is stratified sampling?

Answer 21

The population is divided into categories that are then sampled proportionally.

Question 22

What counts as qualitative data?

Answer 22

It is subjective and descriptive

Question 23

What counts as quantatitive data?

Answer 23

It can be measured objectively, usually with numerical value

Question 24

What is ranked data?

Answer 24

Numerical values are replaced by their rank from lowest to highest

Question 25

Correlation is an ______ but does not imply _____

Answer 25

Correlation is an association and does not imply causation

Question 26

Causation exists if?

Answer 26

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

Question 27

A positive correlation exists when...

Answer 27

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

Question 28

A negative correlation exists when...

Answer 28

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

Question 29

What is the entire scientific cycle?

Answer 29

Hypothesis, experimental design, gathering and recording, analysis of data, evaluation of results, conclusion

Question 30

What is the null hypothesis?

Answer 30

Essentially the 'no change position' where you state there is no relationship between two variables

Question 31

What is the alternative hypothesis and when is it used?

Answer 31

It is the opposite of the null hypothesis and is used when the null is disproven and rejected

Question 32

Scientific ideas only become accepted when?

Answer 32

They have been checked independently

Question 33

What are the three techniques used in animal studies to ensure ethically correctness

Answer 33

Replace, reduce and refine

Question 34

In human studies, what things must be put in place ?

Answer 34

Informed consent, the right to withdraw data at any time and confidentiality

Question 35

Background information should be?

Answer 35

Clear, relevant and unambigious.

Question 36

Statistical tests are used to?

Answer 36

Determine whether the differences between the means are likely or unlikely to have occurred by chance.

Question 37

What do error bars do?

Answer 37

Indicate the variability of data around the mean.