Experimental Methods

Question 1

What is an aim

Answer 1

a general statement of what the research intends to investigate, the purpose of the study

Question 2

What is a hypothesis

Answer 2

• stated at the beginning of a study
• a clear, testable statement that states what is believed to happen/be true

Question 3

What’s the difference between a directional and non-directional hypothesis?

Answer 3

directional states the kind of difference/relationship between two conditions/participants whereas non-directional simply states that there is a difference

Question 4

What are variables

Answer 4

• anything that can change or vary within an investigation
• generally used to determine if changes in one thing result in changes in another

Question 5

what is a null hypothesis

Answer 5

it is a statement of no difference/no relationship; results will be due to chance

Question 6

What is operationalisation

Answer 6

when you define a variable by specifying a set of observations or behaviours that can be measured

Question 7

What is standardisation

Answer 7

all participants in a study have exactly the same experience so that individual experience does not cause some participants to engage in the study differently

Question 8

What are extraneous variables

Answer 8

• variables that have unwanted effects and can come from random error
• researchers try to ensure that extraneous variables have as little effect as possible on the outcome

Question 9

What is random error and where can it come from

Answer 9

something which can’t be predicted such Pp state of mind
can come from a lack of standardisation

Question 10

How can researchers work around random error

Answer 10

randomly allocate Pp to different experimental conditions do that the effect of errors can be balanced out

Question 11

What is a pilot study

Answer 11

it is a small trial run of a research design before the real investigation to ensure everything works correctly and if not can be corrected before completing the actual experiment

Question 12

What are the 3 types of extraneous variables

Answer 12

Participant Variables;
factors such as Pp age/intelligence

Situational Variables;
factors to do with the experimental setting and environment such as sound/temperature

Experimenter Variables;
changes in the personality, appearance and conduct of the researcher which can affect the experiment

Question 13

What are confounding variables

Answer 13

come from constant errors
have an effect of the dependent variable making it impossible to say that any effects were directly caused by the IV

Question 14

What are demand characteristics

Answer 14

they occur when Pp try to guess the aim of the experiment and act accordingly which fails to tell us about real life behaviour as Pp may purposely over/under perform, affecting the DV

Question 15

How can you reduce demand characteristics

Answer 15

use a single blind procedure which involves Pp having no idea of which condition of a study they are in

Question 16

What are investigator effects

Answer 16

ways in which researchers unconsciously influence results of research through physical characteristics (age), personal characteristics (tone of voice), bias

Question 17

How can you reduce investigator effects

Answer 17

double blind technique which is when Pp and investigators are unaware of the aim of the experiment; this prevents researchers unconsciously giving Pp clues

Question 18

What are control groups

Answer 18

used to ensure results are not due to chance
involves a group who have not experienced any condition so if results are found for the experimental condition then it can be assumed that it is due to the IV

Question 19

What is counter balancing

Answer 19

ensures that each condition is tested first or second in equal amounts

Question 20

What are the three main types of experiment

Answer 20

Lab
Natural
Field

Question 21

What do Lab experiments involve

Answer 21

highly controlled environment using standardised procedures
the IV and DV are precisely operationalised and measured leading to greater accuracy and objectivity, allowing for greater replication and enabling inter-rate reliability

Question 22

What are disadvantages of lab experiments

Answer 22

experimenter bias where experimenters expectations can affect results and Pp may be influenced by these expectations
low ecological validity as high levels of control create artificial situations so difficult to generalise
Pp may also be aware they are being tested, possibly creating demand characteristics

Question 23

What do Field experiments involve

Answer 23

performed in a real-world setting where the IV is manipulated and as many variables as possible are controlled
use real scenarios but include confederates to manipulate the IV, this allows for some control whilst improving ecological validity
these relate more to everyday situations so has high levels of mundane realism and can more easily be generalised to real world behaviours and reduce demand characteristics

Question 24

What are disadvantages of field experiments

Answer 24

more difficult to control extraneous variables so hard to establish causality

conditions are never exactly the same again so it is difficult to repeat experiment in exact same way, meaning results can’t be checked

also may be ethical issues as Pp often are unaware they are being tested and do not provide informed consent

Question 25

What do natural experiments involve

Answer 25

the researcher does not manipulate the IV, the IV varies naturally and the researchers records the effect on the DV
natural and quasi experiments are often used when it is unethical to manipulate the IV
Random allocation of Pp is not possible
high ecological validity and can be generalised easily

Question 26

What are disadvantages of natural experiments

Answer 26

it is even harder to control extraneous variables so causality is hard to establish
conditions are rarely the same so unable to repeat experiment; lack of reliability
ethical issues as Pp often unaware they are being tested and do not provide informed consent
Pp not randomly allocated so may be a bias in the sample as Pp variables cannot be controlled

Question 27

What are the three types of experimental design

Answer 27

Independent groups
Repeated measures
Matched Pairs

Question 28

What is an independent groups design

Answer 28

different Pp are tested against each other as different Pp are used in each condition and only take part in one condition each

Question 29

What are the advantages of independence groups

Answer 29

• no order effects
  each Pp do one condition each so there are no order effects whereby the order of conditions affects performance

No demand characteristics;
Pp only take part in one condition so there is less chance of them guessing the aim of the study

Time saved;
both sets of Pp can be tested at the same time

Question 30

What are the disadvantages of Independent groups

Answer 30

• more Pp needed;
  as Pp only take part in one condition, twice as many Pp are needed as for repeated measures
• group differences
  differences in results between the two conditions may be due to participant variables rather than the manipulation of the IV however this is minimised by random Pp allocation to each condition

Question 31

What is a repeated measures design

Answer 31

each Pp is tested in each condition so Pp are tested against themselves

Question 32

What are the advantages of repeated measures

Answer 32

• group differences
  no Pp variables as Pp are tested against themselves making it easier to establish cause and effect
• more data with fewer Pp
  fewer Pp are needed overall to produce the same amount of data as an independent groups

Question 33

What are the disadvantages of repeated measures

Answer 33

• order effects
  as different Pp take place in all conditions, there are order effects whereby the order of conditions affects performance

demand characteristics;
due to taking part in both conditions Pp are more likely to guess the aim and act accordingly

Time consuming;
a gap may be needed between both conditioned meaning the experiment takes longer to conduct

Question 34

What is matched pairs design

Answer 34

this is where Pp are matched on characteristics first such as age
identical twins would ensure maximum matching

Question 35

What are the advantages of matched pairs

Answer 35

No order effects;
different Pp do one condition each so there are no order effects whereby the order of conditions affect performance

No demand characteristics;
Pp only do one condition so less likely they will guess aim of study

Group differences;
less chance of Pp variables

Question 36

What are the disadvantages of matched pairs

Answer 36

more Pp needed;
experiment requires more Pp and each Pp takes part in one condition

Matching is difficult;
impossible to match all variables between Pp and unmatched variables may effect results

Time consuming;
lengthy process to match and test Pp