Approaches and Research

Methods

•How to write the perfect study for the 2nd

paper

A2 Psychology for OCR exam board (can

also be used in conjunction with the AS

spec.)

Strengths & Weaknesses of

Experiment Types

STRENGTHS

more control of the

experiment

More ethical as it is

easy to get consent

WEAKNESSES

Lacks ecological

validity – not in

natural setting

High demand

characteristics as

they can see what

is expected of them

Strengths & Weaknesses of

Experiment Types

STRENGTHS

Higher ecological

validity

Lower demand

characteristics

WEAKNESSES

Can be unethical:

difficult to get

consent e.g.

Piliavin

Experimenter has

less controlPiliavin

Strengths & Weaknesses of

Experiment Types

STRENGTHS

Higher ecological

validity as there is

no tempering with

the IV

WEAKNESSES

Difficult to repeat

as the IV is

naturally occurring

Design of the Experiment

STRENGTHS

Less demand

characteristics as

they will not learn

conditions

WEAKNESSES

More difficult to

compare as there

could be several

reasons such as

gender etc.

Design of the Experiment

STRENGTHS

More accurate and

easy to compare

the results

Costs less than

getting twice as

many participants

WEAKNESSES

Demand

characteristics:

participants may

become familiar

with what is

expected

Design of the Experiment

STRENGTHS

Less demand

characteristics as

the study won’t be

learnt over time

WEAKNESSES

Using different

participants in

same condition not

as accurate as

originally thought to

be

Appropriate Hypothesis

Alternate hypothesis◦ Testable statement that proposes the expected

outcome of the study

◦ Suggests significant difference between results of the two conditions

Null hypothesis◦ Findings not consequences of predicted effect

but due to chance

Two-tailed hypothesis◦ Predict that the outcome could fall in one of two

directions

One-tailed hypothesis◦ Predict that the outcome will fall in one direction

Operationalising a Hypothesis

Hypothesis should contain a clear

statement of the IV and the DV as well

as the word ‘significant’ and an

indication as to whether it is one-

tailed, two-tailed or null.

People in a village will post a

significantly greater number of

apparently mislaid letters than

people in a city [example]

The Procedure IV – if looking for differences between 2 people, you need 2

groups of participants. This is the variable that CHANGES

DV – this has an effect on the materials used to measure this variable. This is the variable that is MEASURED

Controls – ensure extraneous variables are controlled as far as possible (particularly for simple things such as age, gender etc.)

Ethical guidelines – ensure the study follows for participants:

1. Consent

2. No deception

3. Right to withdraw

4. No psychological harm

5. Confidentiality

6. Debreifing

A step by step procedure of what participants will be doing is ideal

The Procedure continued...

Ethical guidelines – ensure the study follows for participants:1. Consent

2. No deception

3. Right to withdraw

4. No psychological harm

5. Confidentiality

6. Debriefing

A step by step procedure of what participants will be doing is ideal

Decide on a Sample

STRENGTHS

Varied selection of

participants

WEAKNESSES

Can be

ethnocentric

(biased towards

experimenters

cultural influence)

Available Participants

Decide on a Sample

STRENGTHS

Completely fair

Mixture of

participants

WEAKNESSES

No theory behind

how sample is

chosen

An equal chance of being chosen

Decide on a Sample

STRENGTHS

Ethically sound

◦ Informed consent

received

WEAKNESSES

Not always a

varied sample

◦ Participants may

have time

◦ Participants may be

more motivated

Volunteers