Unit 3 – Research Methods


Hypotheses – a prediction about what will happen in the research

Null hypothesis – a statement which predicts no difference of correlation

Alternate hypothesis – a statement which predicts a difference or correlation

Variables – anything that is open to change

Independent variable: something that the researcher changes or manipulates

Dependent variable: something that is measured to see if it has changed

Extraneous variables – a variable (not the IV) that could affect the DV if it is not controlled

Standardisation – a way of controlling extraneous variables; to keep variables the same across conditions



Experimental design – a way of allocating participants to conditions in an experiment

Repeated measures – where the participant takes part in each condition (e.g. Terry)

–Advantage: comparing the same participant in each condition – cuts out individual differences. Need less participants

–Disadvantage: order effects – can perform worse in 2nd trial if bored, tired or know the experiment

Independent groups – where participants are different in each condition

–Advantage: no order effects

–Disadvantage: individual differences between each group could explain the results rather than changing IV



Sample – small group of people representative of target population

Random sampling: drawing participants by chance (out of a hat). No bias in who is chosen, gives a good cross section of people. Not always practical, especially with large population

Opportunity sampling: selecting people who are convenient and willing to take part (e.g. in school or on local street). Tends not to be representative but is quick and easy to use.

Ethics: making sure participants aren’t personally affected by the research

Informed consent when participants agree to take part in a study and know what the aim of the study is

Right to withdraw when participants are allowed to stop participating in a study or can stop the study altogether

Confidentiality all participants information is kept confidential and safe from other’s seeing it

Protection of participants participant comes under no physical, emotional or psychological harm during the research



Method Detail Advantages Disadvantages Example
Lab experiment Change IV and measure DV

In a laboratory, controlled conditions

Control over variables

Can see cause and effect

Lacks ecological validity

Effect of setting

Demand characteristics

Field experiment In a natural environment but still manipulate IV More ecologically valid

More applicable to real life

Ethical problems

Less control over variables

Observation Can be overt (known) or covert (secret)

Can be participant (researcher part of group) or non-participant (just watches)

Covert – People behave naturally

Overt – more ethical

overt- – behave differently if being watched

Covert – non ethical

Observer bias – are they seeing what they want to see?

Strange situation
Interview Structured – set questions

Unstructured – themed but not set in stone

Access thoughts and feelings

Can double check understanding

People may lie/exaggerate

Not everyone can explain their feelings

Time consuming

Diamond and Sigmondson
Questionnaire Can be open (opinion) or closed (yes/no) question Access thoughts and feelings

Quick and easy to use

Same questions asked

People may lie/exaggerate

May not understand Q

Individual differences ignored

Hazan and Shaver


Method Detail Advantages Disadvantages Example
Case study In depth analysis of one person or a small group Lots of in depth informationApplicable to similar situations Cannot generalise outside of small sampleTime consuming Diamond and Sigmondson
Correlation To see if there is an association between two sets of data

Positive, negative, no correlation

Can see relationships between variables No correlation doesn’t tell us enough
Longitudinal studies A study carried out over a long period of time Useful for studying psychological development Time consuming

Drop out rate high

Diamond and Sigmondson
Cross Sectional studies Comparing groups of different stages of development Quicker

Less drop out

Not actually comparing the same people Piaget



Qualitative data – descriptive data, normally in the form of words or images

Quantitative data – numerical data – any measurement

Descriptive data

Mode – the most popular score in a data set

Median – the middle score when a data set is put in order

Mean – the total of a data set divided by the number of scores in it



Table – a way of presenting data by summarising it under headings

Bar chart – a chart that summarises data by using bars to represent the different frequencies of categories

Line graph – A graph that summarises data using a line to show changes in the frequencies of scores



Validity – whether the results are true or real

Ecological validity – does it reflect real-life surroundings

Reliability – is it consistent? If carried out again will the same results come up?

Inter-rater reliability – when two (or more) researchers agree on their findings

Demand characteristics – cues in an experiment, which give away the aim

Observer effect – when participants behave differently from normal because they know they are being observed

Social desirability – responses that participants give when they say what they believe the researcher wants to hear



Bias – only viewing things from a certain perspective

Gender bias – where one gender is favoured over another (used to be males in research)

Cultural bias – where one culture is favoured over another (usually USA or Western)

Experimenter bias – setting up an experiment and/or interpreting the results to fit a certain theory or idea.


Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out /  Change )

Google+ photo

You are commenting using your Google+ account. Log Out /  Change )

Twitter picture

You are commenting using your Twitter account. Log Out /  Change )

Facebook photo

You are commenting using your Facebook account. Log Out /  Change )


Connecting to %s