Research methods- Experimental method

Question 1

Aim

Answer 1

Purpose of study
To investigate…

Question 2

Experimental hypothesis

Answer 2

Clear precise, testable statement that states the relationship between the variables to be investigated. - Outset of study.

Question 3

Directional hypothesis (one tailed)

Answer 3

difference anticipated made clear between the two conditions
: more, less, higher, lower, faster, slower

Question 4

Non-directional hypothesis (two tailed)

Answer 4

Nature of difference not specified.

Question 5

Null hypothesis

Answer 5

No significant difference between two groups.

Question 6

Independent Variable

Answer 6

Manipulated by researcher or changes naturally

Question 7

Dependent variable

Answer 7

Measured by the researcher

Question 8

Conditions

Answer 8

Different testing groups which reflect what independent variable is.

Question 9

Operationalisation

Answer 9

Clearly defining variables into measurable factors.
Variables ‘operationalised’ when writing hypothesis

Question 10

Extraneous variable

Answer 10

Additional unwanted variables that might potentially interfere or change the Dv.

Question 11

Confounding variables

Answer 11

Extraneous variables that have systematically changed with the Iv.

Question 12

Investigator effects

Answer 12

Any effect of the investigator’s behaviour on the research outcome.

Question 13

Demand characteristics

Answer 13

Participants picking up cues from the researcher or research situation, revealing the purpose of the investigation may lead to the participant changing their behaviour.
Please you, screw you affect.

Question 14

Randomisation

Answer 14

The use of chance wherever possible to control for the effects of bias.

Question 15

Standardisation

Answer 15

As far as possible all participants should be subject to the same environment, information and experience.
Standardised instructions read to each participant.

Question 16

Experimental Design

Answer 16

The way in which participants are used in experiments.
How participants are assigned to different conditions.

Question 17

Order effects

Answer 17

Any effect of doing one condition followed by another.
Order in which info is presented influences participant’s response.

Question 18

Independent groups

Answer 18

Participants take part in only one condition.
Results then compared.
ADV:
- No order effects (only take part once)
-Participants less likely to guess aim
- Only one test needed
DISADV: Not the same participants so differences between the two groups may be because of individual differences.
- Two groups of participants needed.

Question 19

Repeated Measures

Answer 19

Participants experience both conditions
Results then compared
Weaknesses:
- Order effects are a problem
- Demand characteristics are a problem as participants guess the aim
- More than one test needed
Strengths:
- Participant variables not an issue as same participants in both conditions
- Less participants needed so more economical

Question 20

Matched paris

Answer 20

2 separate groups of participants
Paired on key characteristics
Tries to control participant variables
STRENGTHS:
- No order effect as participants only in one condition
- Less demand characteristics
WEAKNESSES:
- Still participant variables as cant match exactly
- Matching is time consuming and expensive
- Less economical

Question 21

Counterbalancing

Answer 21

An attempt to minimise the effects of order effects in a repeated measure design.
Attempts to balance out order effects but can’t get rid of them.

Half participants do condition A then B.
Half participants do condition B then A.

Question 22

Random allocation

Answer 22

Used in independent groups
Participants randomly allocated to conditions using random techniques to address the problem of participant variables in the two conditions.
Avoids bias
Evenly distributes participant characteristics across the conditions of the experiment using random techniques

Question 23

4 types of experiment

Answer 23

lab, field, nature, quasi

Question 24

lab experiments

Answer 24

Researcher manipulates the IV.
Takes place in artificial, controlled setting

STRENGTHS:
- high control over extraneous variables
- more confidence that Iv has affected Dv
- replication is possible because of control

WEAKNESSES:
- lack generalisability to other settings
- in particular, lacks generalisability to real life
- participants more likely to act unnaturally- demand characteristics
- lacks mundane realism

Question 25

field experiments

Answer 25

iv manipulated by researcher
setting more natural

STRENGTHS:
- higher mundane realism than lab
- behaviour more valid and authentic
- participants may be unaware they’re being studied

WEAKNESSES:
- less control over extraneous variables
- cause and effect between iv and dv more difficult to establish
- precise replication not possible
- ethical issues
- possible invasion of privacy

Question 26

natural experiments

Answer 26

Researcher doesn’t manipulate IV.
IV is an event which occurs naturally

STRENGTHS:
- Provides opportunities for research that may not be otherwise undertaken.
- high external validity as they study real-life issues and problems e.g. natural disaster

WEAKNESSES:
- natural disasters only happen rarely, reducing opportunities for research
- Generalising findings to other similar situations will be limited

Question 27

Quasi experiment

Answer 27

Researcher doesn’t manipulate IV.
IV is a feature of the participants e.g. gender

STRENGTHS:
- Often carried out under controlled conditions, therefore share same strengths as lab experiment

WEAKNESSES:
- Cannot randomly allocate participants to conditions (already in them)
- Therefore may be confounding variables.

Question 28

Single-blind procedure

Answer 28

Participants not told aim of study + not told what condition of experiment they are in.

An attempt to control the effects of the demand characteristics

Question 29

Double-blind procedures

Answer 29

Neither researcher or participants know the aim.
Often third party conducts the investigation without knowing its purpose.

Question 30

Control groups and conditions
(Drug Trial Example)

Answer 30

Experimental condition- real drug
Control condition- Placebo

Question 31

Pilot studies

Answer 31

Small scale trial run of the actual investigation
Handful of participants
Helpful with other methods
Observation studies: provides a way of checking behavioural categories in use
Researcher can identify potential issues, modify procedure to save time + money.