experiments

Question 1

experiment

Answer 1

an experimental research method investigates cause-and-effect relationships by determining if one variable effects another.
the researcher begins with an aim, then formulates a hypothesis to test the potential causal relationship.

types of experimental methods; lab, field, natural and quasi

Question 2

aim

Answer 2

statement of what the researcher intends to find out

Question 3

hypothesis

Answer 3

prediction of what they expect to find from the research
you need to know the operationalised independent and dependent variable.

psychologists start their research with both a null and experimental hypothesis and then reject the one that doesn’t support the research

Question 4

independent variable

Answer 4

variable that the psychologist changes
will lead to two or more conditions
the cause

Question 5

dependent variable

Answer 5

variable that is measured to see if it changed e.g. number of..
the effect

Question 6

operationalisation

Answer 6

researcher must assure IV and DV are operationalised - they are both specific and measurable
allows researcher or anybody else to repeat the study the same way to check results

Question 7

alternative/experimental hypothesis

Answer 7

predicts a difference
“there will be a difference (DV)(condition 1)(condition 2)
there are two types: directional and non-directional

Question 8

null hypothesis

Answer 8

predicts no difference
“there will be no difference in (DV)(condition 1)(condition 2)

Question 9

directional hypothesis (one-tailed)

Answer 9

states which specific direction the results will go in. contains words like ‘there will be more/less’ ‘higher/lower’
may be used when findings of a previous effect point to a particular direction

Question 10

non-directional hypothesis

Answer 10

less clear of the direction
‘there will be a difference’
psychologists may use this if previous research is less or if findings show no consistent direction

Question 11

extraneous variable

Answer 11

can affect the DV if not controlled. consists of 3 types: participant, situational, experimenter

Question 12

participant variables

Answer 12

differences between participants e.g. age, gender, prior knowledge and experiences

Question 13

situational variables

Answer 13

differences in the environment such as the time of day or temperature or noise

Question 14

experimenter variables

Answer 14

the tone of voice or body language the experimenter uses or bias

Question 15

standardised procedures or matched pairs

Answer 15

method to control situational variables

ensure all pts are tested under the same conditions - avoid situational variables

Question 16

repeated measures design or matched pairs

Answer 16

control participant variables

repeated measures: same pts used in every condition

matches pairs: match a pt from each condition on the basis of a key variable e.g. age.
pairs are then compared rather than whole groups

generally, psychologists should just design a study that makes it hard for pts to guess the aims of the study

Question 17

double blind technique

Answer 17

control of experimenter variables

the person who carries out the research is not the same as the one who designed it

Question 18

demand characteristics

Answer 18

structure of the study could lead to a pt guessing the aim of the study - can lead to them changing their behaviour - artificial - lowers validity

Question 19

laboratory experiment

Answer 19

investigates causal relationships between an IV and a DV under controlled conditions

conducted in a special environment where variables are controlled - usually a university lab

Question 20

strengths of laboratory experiment

Answer 20

strengths:
manipulation of IV under controlled conditions allows cause & effect to be established as EVs are controlled
easy to replicate due to standardised procedure

Question 21

weakness of laboratory experiment

Answer 21

weakness:
experiments are artificial which may produce artificial behaviour - low ecological validity
low mundane realism - whether the task relates to real life tasks
ethical problems - deception, potential harm etc

Question 22

field experiment

Answer 22

investigates causal relationships between IV and DV in a more natural environment.

pts may not be aware they are participating
researcher still manipulates the IV e.g. at a school vs casino

Question 23

strength of field experiment

Answer 23

strengths:
higher mundane realism
less chance of demand characteristics - pts are not aware - can’t change behaviour as they don’t know the aims of the study.
easy to generalise results to our settings

Question 24

weakness of field experiment

Answer 24

weaknesses:
ethical issues; deception, invading privacy, potential harm etc
difficult to control EVs - less validity - cannot measure what we intended to measure

Question 25

natural experiment

Answer 25

investigates relationship between IV and DV but IV cannot be directly manipulated - so the IV varies naturally e.g. researching prisoners, kids in an orphanage - more extremal

Question 26

strength of natural experiment

Answer 26

strengths: allows psychologists to carry out research where the IV cannot be manipulated for ethical reasons or practical reasons allows psychologists to study real problems - increases mundane realism and ecological validity

Question 27

weakness of natural experiment

Answer 27

weaknesses: cannot demonstrate casual relationships between IV and DV random allocation not possible therefore there may be EVs that cannot be controlled - lowers validity

Question 28

quasi-experiment

Answer 28

investigates relationships between IV and DV but IV cannot be directly manipulated - IV varies naturally. IV is a characteristic of a person e.g. mental disorders, gender, personality - more internal

Question 29

strength of quasi-experiment

Answer 29

strengths: allows psychologists to carry out research where the IV can't be manipulated for ethical/practical reasons allows them to study real problems - increases mundane realism and ecological validity

Question 30

weakness of quasi-experiment

Answer 30

weaknesses: cannot demonstrate casual relationships as IV is not manipulated random allocation is not possible - may be EVs that can't be controlled - lowers the validity

Question 31

experimental designs

Answer 31

once researcher has chosen experimental method that suits the nature of the study best, they choose the type of design there are 3 types: independent groups, repeated measures and matched pairs

Question 32

independent groups

Answer 32

one set of participants who only represent one condition of the IV

Question 33

advantages of independent groups

Answer 33

eliminate order effects - pts only take part in one condition pts are less likely to guess the aim of the study and show demand characteristics

Question 34

disadvantages of independent groups

Answer 34

cannot control effects of participant variables to improve this - randomly allocate pts to conditions to distribute variables easily

Question 35

advantages of matched pairs

Answer 35

eliminate order effects - pts only take part in one condition less likely to guess aim and show demand characteristics

Question 36

disadvantages of matched pairs

Answer 36

cannot control all participant variables to improve this, conduct a pilot study to consider key variables that are important when matching

Question 37

advantages of repeated measures

Answer 37

eliminate PVs

Question 38

disadvantages of repeated measures

Answer 38

order effects are likely more likely to guess aim of the study and show demand characteristics to improve this researchers may use 2 different tests to reduce order effects. there are 2 techniques to tackle order effects; counterbalancing and randomisation

Question 39

counterbalancing

Answer 39

alternating the order in which participants perform in different conditions. e.g. group A does condition 1 first then condition 2, and group B do condition 2 then condition 1

Question 40

randomisation

Answer 40

material for each condition is presented in a different order e.g. same words are presented but in a different order for each pt.

Question 41

random allocation (for independent groups design)

Answer 41

using a non-biased method to allocate pts to conditions. this will evenly distribute PVs across all conditions, so PVs are less likely to affect the results e.g. putting all pts names into a hat then the first person drawn is allocated to condition 1. then the second person drawn to condition 2. the third person to drawn condition 1 and so on. this greatly decreases systematic error as well as researcher bias

Question 42

reliability

Answer 42

how consistent the results are. if study is repeated, the same or highly similar results should occur again

Question 43

validity

Answer 43

extent to which a test measures what it intended to measure

Question 44

ecological validity

Answer 44

extent to which you can apply the findings of the study to other situations/environments outside the setting of the study

Question 45

control

Answer 45

how well the researcher has controlled the variables - without control we cannot state that it was the IV that changed the DV

Question 46

mundane realism

Answer 46

how well an experiment task reflects real life tasks - the higher the mundane realism, higher the ecological validity

Question 47

internal validity

Answer 47

refers to things that happen INSIDE the study such as whether we can be certain that it was the IV which caused changed in the DV internal validity can be affected by a lack of mundane realism - lead the pts to act in an unnatural way - less valid results can also be affected by EVs

Question 48

external validity

Answer 48

whether the study is a true representation of behaviour outside of the specific experimental setting

Question 49

population validity

Answer 49

extent to which you can generalise the findings to the rest of the population

Question 50

temporal/historical validity

Answer 50

extent to which we can generalise the findings to other time periods

Question 51

pilot studies

Answer 51

a trial run on a small scale study conducted on a small sample and aims to test all aspects; procedure, flaws in design, check materials used. a way to check that everything in your actual experiment will run smoothly and help to improve validity find flaws before time and money is invested in carrying out a large study