Experimentation

Question 1

Validity

Answer 1

Variables controlled so that my measured effect is likely to be due to the independent variable.

Question 2

Reliability

Answer 2

Consistent values in repeats and independent replicates

Question 3

Accuracy

Answer 3

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

Question 4

Precision

Answer 4

Measured values ne close to each other

Question 5

What is a pilot study used for?

Answer 5

To help plan procedures, assess validity and check techniques

Question 6

Simple experiments

Answer 6

One independent variable

Question 7

Multifactorial experiments

Answer 7

More then one independent variable

Question 8

Drawback of simple experiments

Answer 8

Its findings may not be applicable to a wider setting

Question 9

When is there no truly independent variable?

Answer 9

When investigators use groups that already exist.

Question 10

Drawback of observational studies

Answer 10

Since key do not directly test a hypothesis, they are less useful for determining causation

Question 11

What happens to the independent variable in observational studies?

Answer 11

It is not directly controlled by the investigator, for ethical or logistical reasons.

Question 12

Randomised block design

Answer 12

Makes the influence of cry confounding variables likely to be the same across the treatment and control groups.

Question 13

Negative central

Answer 13

Provides results in the absence of treatment

Question 14

Positive control

Answer 14

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

Question 15

Placebos

Answer 15

A treatment without the presence of the independent variable being investigated.

Question 16

Placebo effect

Answer 16

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

Question 17

In vitro

Answer 17

Refers to the technique of performing a given procedure in a controlled environment outside of a living organism.

Question 18

In Viva

Answer 18

Refers to experimentation using a whole, living organism.

Question 19

When is a representative sample of the population selected?

Answer 19

Where it is impractical to measure every individual

Question 20

What determines the appropriate sample size?

Answer 20

The extent of the natural variation within a population.

Question 21

How can a population be representative?

Answer 21

The sample should share the same mean and the same degree of variation about the meant as the population as a whole.

Question 22

Random sampling

Answer 22

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

Question 23

Systematic sampling

Answer 23

Members of a population are selected at a regular interval.

Question 24

Stratified sampling

Answer 24

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

Question 25

Qualitative data

Answer 25

Subjective and descriptive

Question 26

Quantitative data

Answer 26

Can be measured objectively, usually with a numerical value.

Question 27

Ranked data

Answer 27

Numerical values are replaced by their rank when the data are sorted from lowest to highest

Question 28

When does causation exist?

Answer 28

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