Research Methods

(Whitehead / Arthur)

Laboratory experiment:- carried out in a lab setting

- Highest level of control - Repeatable, therefore

reliable if similar results are produced

- Can use sophisticated measuring equipment in a lab

- More control over variables (could lead to knowing the cause/effect)

- Loss of validity (esp. ecological validity)

- Demand characteristics.

Field Experiment:- carried out in their natural environment

• Improved ecological validity

• Reduction of demand characteristics (though there may still be some)

• Less control over IV and measuring DV. With addition of EV’s (extraneous variables)

• Results cannot be generalised to other situations

• Often more costly (as things have to be arranged outside – could inc. technical equipment)

Natural experiment:- IV is naturally occurring

• Reduction of demand characteristics

• The investigator doesn’t intervene (however, the presence of an investigator could affect ppts behaviour)

• Loss of control – The investigator doesn’t control the IV.

• A cause/effect relationship is difficult to establish

Correlation: - a term that refers to the extent to which values co-vary

• Measures the strength of relationships

• No cause/effect can be measured

+ 1 = perfect positive correlation

-1 = perfect negative correlation

Observation: - No deliberate manipulation of the variables

Naturalistic:Observed in a natural environment, e.g. school or workplace.

Lab-based observation:Labs can be ‘dressed up’ to look more natural, like a playroom, where children can be observed using a one-way mirror.

Observation – evaluation:

• Good research can be collected

• Ecological validity can be good

• Control – cause/effect relationship cannot be established

• Replication may be difficult due to variables

• Observer effects/demand characteristics

• Ecological validity may be lower

• Costs can be high

Self report: Questionnaires:

• Closed questions – Tickboxes

• Open ended questions – ‘What are your views on…?’

• Leading questions – You love this PowerPoint, don’t you?

• Simple• Cheap & quite quick• Researcher doesn’t

intrude• Ambiguous questions

could be misconstrued• Leading Q’s• Social desirability bias

Self report: Interviews:

• Structured interviews – set set of Q’s

• Unstructured interviews – Q’s aren’t decided in advance

• Semi-structured interviews – Some Q’s are pre-prepared, however the investigator is free to add more during the interview

• Flexible (In semi&unstructured)

• Able to tackle personal topics

• Data can be misinterpreted• Time consuming• Interviewees may not be

able to convey their thoughts

• Demand characteristics / social desirability bias

Case studies

• In depth studies• Rich/interesting data

• Not generalisable - they’re unique to the individual (or small group)

• Findings may be subjective

• Lots of data to chose from

Quantitative & Qualitative:

Quantitative data:Tends to be numerical. Comes from things like

tick boxes. (easily processed)

Qualitative data:Data received from longer answer questions,

often from interviews. (gives more detail)

Hypothesis’:

• Directional hypothesis:Predicts the direction in which results will occur. E.g. ‘More

words are recalled from a list when using rehearsal as a mnemonic technique than when no technique is being used.’

• Non-directional hypothesis:Does not predict the direction of the outcome: ‘There is a

difference in the number of words recalled from word lists presented with or without background music’

• Null hypothesis:Would predict that the IV would have no effect. E.g. ‘Using

mnemonic techniques will not improve memory’

Experimental design:

Independent groups:Using different participants for each condition of the experiment.Matched pairs:Matching each ppt with someone who is similar to them, and placing them in different conditions.Repeated measures:Exposing each ppt to each condition, so the ppts are (technically) their own controls.

DV and IV

• Dependent variable:The variable that is assumed to be effected by the IV. Changes in the DV are presumed to have been caused by the IV.

• Independent variable:The variable which is manipulated by the experimenter that is presumed to effect the DV.

Operationalising the variable:

General statement: ‘Mnemonics improve memory’

It means ‘narrowing down the research focus’

So, figuring out the most simple IV and DV from a question.

Pilot study:

• Small scale trial run of the actual experiment• Allows the investigator to identify flaws of the

experiment• Tests for problems with

- design of the experiment- Clarity of instructions for the ppts- Measuring instruments

• Also allows a time scale of the actual experiment to be estimated

Extraneous variables:

• Should (try to) be controlled so as not to affect the IV or the DV

Reliability & Validity:

Reliability:Test whether something is reliable or not by doing

repeats & seeing if similar results are gathered.

Validity:Ecological validity – the extent to which the findings

can be generalised to outside the research settingPopulation validity – the extent to which the findings

can be generalised to other groups of people

Subjective & objective:

Subjective:‘Based on or influenced by personal feelings,

tastes, or opinions.’

Objective:Data which is based on scientific information. Eg.

Using blood samples would be considered objective.

Ethical issues:

• Informed consent (though, sometimes presumptive consent is used on the basis that the investigator would think that they’d get consent)

• Confidentiality• Right to withdraw• Deception• Protection from harm• Debriefing

Cost-benefit analysis:

Is the cost of the experiment worth the amount of data we would get?

Types of sampling:

1. Random sampling- Everyone in the population has an equal chance of participating. E.g. using a random number generator to find numbers

2. Opportunity sampling- Unlikely to generate a representative sample, so investigation could be offered to everyone at a school, but then results couldn’t be generalised externally.

3. Volunteer sampling- People sign up to the experiment (e.g. in Milgram 1960) Unlikely to be generalisable, as people who sign up are most likely to have a certain personality type

Demand characteristics:

• Predicting what the experiment is going to measure and acting accordingly – which could hinder results

• Acting out-of-character due to surrounding environment

• Displaying social desirability bias

Investigator effects – When the investigator can get too involved in the experiment, causing a change in results

Measures of central tendency and dispersion:

• Central tendency:- Mean (add up all no. Divide by amount of data)

- Median (middle number when arranged numerically)

- Mode (most frequently occurring no.)• Dispersion – ‘shows the spread of data’:- Range (highest score – lowest score)- Standard deviation

Points on the spec. Not covered in this PowerPoint:

• How to reduce investigator effects• Be able to present quantitative data in

appropriate graphs• Define types of reliability• Analyse and interpret correlation data• Define and know how to do content analysis• Present qualitative data in a ticklist/table• Pro’s and con’s of the matched pairs, independent

measures, and repeat designs