3.d. Experimental design (27)

Question 1

What is an independent variable?

Answer 1

The variable that is changed in an experiment.

Question 2

What is a dependent variable?

Answer 2

The variable that is measured in an experiment.

Question 3

What can independent and dependent variable be?

Answer 3

discrete or continuous.

Question 4

What is discrete and how can data be shown?

Answer 4

Distinct and unrelated value and plotted using a bar graph.

Question 5

What is continuous and how can data be shown?

Answer 5

Range of values and plotted using a line graph.

Question 6

What do experiments involve the manipulation of?

Answer 6

Independent variable.

Question 7

What are experiment treatment groups compared to?

Answer 7

Control group

Question 8

What can experiments be?

Answer 8

simple or multifactorial

Question 9

What is simple?

Answer 9

There is only one independent variable.

Question 10

What is multifactorial?

Answer 10

There is multiple independent variables.

Question 11

What are the advantages of simple?

Answer 11

Conducted more easily than in field.

Question 12

What are the disadvantages of simple?

Answer 12

Results not applicable to wider setting.

Question 13

What are observational studies good at detecting?

Answer 13

Good at detecting correlation but not causation as is does not directly test the hypothesis.

Question 14

What are confounding variables?

Answer 14

A factor that affects the dependent variable that is not the independent variable.

Question 15

What should confounding variables be held at?

Answer 15

A constant or monitored so their effect can be accounted for in the result.

Question 16

What should you do if the confounding variables cannot be controlled?

Answer 16

Use a randomised block design.

Question 17

What are control groups used for?

Answer 17

For comparison with the results of treatment groups and shows any effects are as a result of the treatment.

Question 18

What are the two types of controls?

Answer 18

Positive and negative

Question 19

What is negative control?

Answer 19

Provides results in the absence of a treatment.

Question 20

What is a positive control?

Answer 20

To check is the system can detect a positive results when it occurs.

Question 21

What are placebos?

Answer 21

Treatment without the presence of the independent variable being investigated.

Question 22

What is the placebo effect?

Answer 22

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

Question 23

What is in vitro studies?

Answer 23

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

Question 24

What are examples of in vitro studies?

Answer 24

• Cells growing in a culture medium
• Proteins in solution
• Purifies organelles

Question 25

What is in vivo studies?

Answer 25

Refers to experimentation using a whole, living organisms.

Question 26

What are the advantages of In vitro?

Answer 26

Confounding variables are easily controlled.

Question 27

What are the disadvantages of in vitro?

Answer 27

Results are limited and may not be transferable to in vivo.

Question 28

What are the advantages of in vivo?

Answer 28

Allows researchers to investigate the overall effect of a drug on living organism.