Experimental designs

Question 1

How is a lab experiment classified?

Answer 1

• The IV is manipulated by the researcher.

- Experiments are done in a controlled environment.

Question 2

How is a field experiment classified?

Answer 2

• The IV is manipulated by the researcher.

- Experiments are done in an uncontrolled/natural environment.

Question 3

How is a natural experiment classified?

Answer 3

• The IV is not manipulated by the researcher.

- The IV is changed by external events.

Question 4

How is a quasi experiment classified?

Answer 4

• The IV is not manipulated by the researcher.

- The IV is influenced by genetic differences.

Question 5

What is the ‘independent groups’ design?

Answer 5

• There are two groups of participants.

- Each group performs in one condition of the IV.

Question 6

What is the ‘matched pairs’ design?

Answer 6

• There are two groups of participants.
• Each group performs in one condition of the IV.
• The groups are made up of pairs of people matched certain characteristics so that the groups have similar reactions.

Question 7

What is the ‘repeated measures’ design?

Answer 7

• There is one group of participants.

- That groups performs both conditions of the IV.

Question 8

What is counterbalancing?

Answer 8

• A solution to some of the issues with the ‘repeated measures’ design.
• The participants are split into two groups and one group completes the IV conditions in the opposite order to the other group.

Question 9

What are order effects?

Answer 9

-A type of extraneous variable caused by the first IV condition which will affect the participant’s performance in the second.

Question 10

What is random allocation?

Answer 10

• A solution to some of the issues with the ‘independent groups’ design.
• Participants are assigned randomly to the IV conditions, limiting researcher bias.

Question 11

What is randomisation?

Answer 11

-The use of chance to reduce the effects of bias.

Question 12

What is standardisation?

Answer 12

-The process of making sure both conditions have very limited difference in experience, excluding the intended change in IV.

Question 13

How and why should a brief be standardised?

Answer 13

• Both groups should be given the same brief, read by a computer.
• This reduces experimenter influence as the computer won’t put emphasis on key words whereas the researcher may.

Question 14

What is ‘opportunity sampling’?

Answer 14

-Selecting anyone who is willing and available to take part in a study at any given time.

Question 15

What is ‘volunteer sampling’?

Answer 15

-Having participants volunteer themselves for a study from an advertisement.

Question 16

What is ‘random sampling’?

Answer 16

-Names of potential participants are put into a hat and randomly pulled out to determine who will take part in a given study. (method of randomisation may vary)

Question 17

What is ‘systematic sampling’?

Answer 17

-Every ‘Nth’ name on a list of potential participants is chosen to take part in a study.

Question 18

What is ‘stratified sampling’?

Answer 18

-Ratios between subgroups are determined within the target population and a sample of participants is taken in proportion to these ratios.

Question 19

What is a single blind procedure?

Answer 19

-A study in which the participant is required not to know all details of the experiment.

Question 20

What is a double blind procedure?

Answer 20

-A study in which the participant and the experimenter are both required not to know all details of the experiment.

Question 21

What are investigator effects?

Answer 21

-Any effects that the researcher may have on the outcome of the research (intentionally or not), this causes bias.

Question 22

What is participant reactivity?

Answer 22

• How likely participant is to exhibit demand characteristics.
• This is an extraneous variable.

Question 23

What is a pilot study?

Answer 23

-A small scale experiment done prior to a study in order to determine whether the experiment is effective.

Question 24

What is the difference between a naturalistic and a controlled observation?

Answer 24

• A naturalistic observation is when a study is done in an uncontrolled environment which is familiar to the participants.
• A controlled observation is done in a controlled environment.

Question 25

What is the difference between a covert and an overt observation?

Answer 25

• In a covert observation, participants are not aware that they are being observed.
• In an overt observation, they are aware.

Question 26

What is the difference between a participant and a non participant observation?

Answer 26

• In a participant observation, the observer, joins the participants in the study.
• In a non participant observation, the observer observes from afar.

Question 27

What is the difference between a structured and an unstructured observation?

Answer 27

• In a structured observation, the observer has a set list of things to be looking out for.
• In an unstructured observation, the observer records everything they notice.

Question 28

What are the two sampling methods for observations?

Answer 28

• Time sampling- noting observations at set time intervals

- Events sampling- taking note every time a certain event occurs.

Question 29

What is inter-rater reliability?

Answer 29

-How accurate or relevant an observer’s results are.

Question 30

How can inter-rater reliability be ensured?

Answer 30

-Usually there are two or more observers independently recording results in order to reduce bias.