3.2 Experimentation

Question 1

Validity

Answer 1

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

Question 2

Reliability

Answer 2

Consistent values in repeats and independent replicates
Reliable = Repeats

Question 3

Accuracy

Answer 3

Data or sets of data that are close to the true value

Question 4

Precision

Answer 4

Measured values are close to one another

Question 5

What is a pilot study

Answer 5

A small scale version of a larger study

Question 6

What is the purpose of a piolet study

Answer 6

Establish the appropriate techniques and number of repeats required
Ensure an appropriate range of value for the independent variable

Question 7

What is discrete variation

Answer 7

Where measurement fall into distinct groups

Question 8

What is continuous variation

Answer 8

Characteristic will have a range of values between a minimum and a maximum

Question 9

What is a simple experiment

Answer 9

One independent variable

Question 10

What is a multifactorial experiment

Answer 10

More than one independent variable

Question 11

What is a observational experiment

Answer 11

A study in which the investigator simply observes and does not change the independent variable

Question 12

What is correlation

Answer 12

When there is a relationship between 2 variables

Question 13

When is causation implied

Answer 13

When the changes in the values of the independent variable are known to cause changes in the dependant variable

Question 14

What is a confounding variable

Answer 14

A variable other than the independent variable that can affect the experiment and must be kept constant

Question 15

What is a randomised block trial

Answer 15

When blocks of treatment and control groups can be distributed in such a way that any influence confounding variables have in likely to be the same across the entire study

Question 16

What is a negative control

Answer 16

Provides results in the absence of treatment

Question 17

What is a positive control

Answer 17

A treatment that is included to ensure the system can detect a positive result

Question 18

Where are placebos mostly used

Answer 18

In human drug trials as a negative control

Question 19

Why are placebos effective

Answer 19

They show a measurable change in the dependant variable as a result of the patients expectations

Question 20

What is a double blind trial

Answer 20

Neither the patient nor the researcher is aware of who has been administered the placebo

Question 21

What is In Vitro

Answer 21

Techniques performed outside of a living organism

Question 22

What is In Vivo

Answer 22

Refers to an experiment using a whole living organism

Question 23

What is representative sampling

Answer 23

Should share the same mean and variation of the population as a whole

Question 24

What is random sampling

Answer 24

Members of public have an equal chance of being selected

Question 25

What is systematic sampling

Answer 25

Member of population selected at regular intervals

Question 26

What is stratified sampling

Answer 26

Population divided into categories and then sampled proportionately

Question 27

What is an independent replicate

Answer 27

Carried out to produce independent data sets

Question 28

Qualitative data

Answer 28

Using your senses to observe results

Question 29

Quantitative data

Answer 29

Measure with numerical data

Question 30

Error Bars

Answer 30

Graphical representations of the variability of data