Research Methods


Volunteer Sampling

- When the participants select themselves to take part in the study

* Easy and time efficient
* All participants will have consented
* Access to a variety of participants
* May produce a large sample

Sample may be biased - May be the same type of people who volunteer e.g students
Sample may not be valid 
Sample may not be representative
Sample may show demand characteristics

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Opportunity Sampling

- Sample collected by asking individuals who are available at the time and fit the criteria you’re looking for.

* Time efficient
* Cost effective
Sample likely to not be representative May try to be seen as socially acceptable/demand characteristicsResearcher bis when selecting

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Random Sampling

- Each member is chosen by chance and everyone has an equal chance of being selected.

* Avoids bias and researcher has no control * Law of probability says the sample is likely to be representative

Time consuming
Chance the sample may not be representative

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- A statement which can be tested to see whether or not it is true.

Research: general prediction ( not enough info to base an investigation on)

Alternate: Enough datail for the experiment to be carried out as components are operationalised. Meaning the variables are measurable

ONE TAILED: "There will be a significant increase..." The hypothesis has a clear direction.

TWO TAILED: "There will be a significant difference..." The hypothesis has no clear direction.

NULL: "There will be no significant difference..." The hypothesis predicts no difference whatsoever.

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Independent Variable: The one you manipulate
Dependent Variable: The one you measure

Extraneaous Variable: Any factor excluding the independent variable which could affect the results (dependent variable).

Confounding Variable: A variable which cannot be controlled. (May do unethical to do so, or mya just be impossible).

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Demand characteristics: Subjects try to make sense of the study they are participating in and adjust their behaviour accordingly.

Social desrability: Subject gives a response which fits in best with the general opinion or view of their peers.

Experimentor bias: The experimentor's expectations or preferences influence the outcome of a study.

Observer Bias: The presence of an observer may change the behaviour of those being observed.

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Whether or not the study measures what it intended to measure.

Internal Validity: Whether the effects observed in the study are due to the manipulation of the independent variable and not another factor.

External Validity: Refers to the extent to which the results os a study can be generalised to other settings.

Face Validity: Whether the measuring tool appears to be doing what it should.

Ecological Validity: Whether the behaviour measured is representative of behaviour that naturally occurs.

Population validity: How well the sample can be used to generalise to the population as a whole.

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The consistency of findings: if the test was repeated using same method would the same results be achieved?

Internal reliability: How consistently a method measures within itself (using one test)

External reliability: The consistency of results over time which repeated

Inter-rater reliabilty: The consistency of different raters working on the same study within their findings

Test re-test method: Participants take same test of different occasions. a high correlation between test scores shows high reliability

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Laboratory Experiment

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Field Experiment

- An experiment carried out in the natural environment

* Can generalise findings
* High in ecological validity
* IV can still be manipulated

Time consuming
Confounding variables make harder to establish cause and effect

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Quasi Experiment

- The experimentor does not manipulate the IV, it is naturally ocuring. Can be tested in the lab or in the field.

* High in ecological validity
* More ethical as subjects are not manipulated

Confounding environmental variables (cannot confidently determine cause and effect)
Have to wait for subjects which characteristics of IV to become available

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Repeated Measures Design

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Independent Measures Design

Different participants used in each condition

* No order effects
* Demand characteristics reduced as subjects only used in one condition

Individual differences may influence results
More subjects needed

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Matched Pairs Design

Uses different paricipants in each condition however they are similar or matched on characteristics, e.g twins are useful.

* Extraneous variables are well controlled
* Individual difeerences reduced

Time consuming

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Standardisation: Method and all instructions made identical for each participant.

Counterbalancing: The researcher changes the order of task for each participant or conditions to try to control or lessen the impact of order effects.

Randomisation: The order of task is randomised in an attempt to control or lessen the impact of order effects.

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To simply observe and record behaviour (no IV is manipulated)

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Covert Observation

The subjects are unaware they are being observed

* No demand characteristics as unaware of study
* High in ecological validty

Difficult to observe without being seen

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Overt Observation

Subjects are aware they are being observed

* Ethical as they have given informed consent
* Easier to conduct

Demand characteristics as subjects may alter behaviour

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Structured Observation

Researcher divises a checklist of the predetermined behaviours they are looking for. Provides qualitative data as the recurrence of behaviours displayed is recorded using a tally.

* Easy to analyse and draw conclusions
* Reliable

Researchers may miss interesting behaviours as not on checklist
Open to researcher bias

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Unstructured Observation

Observer records all behaviours producing qualitative data.

* Provides the researcher with detail
* Less likely to miss important behaviours

Difficult to concerntrate for long periods of time and therefore may not witness all behaviours displayed

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Event Sampling

Observers have predetermined set checklist of behaviours and observe a whole event, tallying behaviours when seen.

* Quantitative data
* Easy to analyse and draw conclusions from

Difficult to concerntrate for long periods of time
May miss important behaviours if not on checklist

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Time Sampling

Observers watch for behaviours for set periods of time in between set intervals of time.

* More focused (Short periods of time)

Observations may not be representative
May miss important behaviours within intervals

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Participant Observation

Participant takes part in the behaviour they are observing

* High in ecological validity
* Reduced demand characteristics

Difficult to simultaneously record behaviour
Observer may influence behaviour

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Non-participant Observation

Participant does not take part in the behaviour which they are observing

* Easier to record information
* Can more easily observe behaviour

Higher demand characteristics if subjects are aware they are being observed
Researcher bias

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Self Report

Used to gather peoples’ opinion and ideas on a topic and to gain an insiders perspective. Administered: Face to face, by post, en masse to a group in public setting, via phone or internet

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Asking a large sample for information on a topic at a particular moment in time

* Large sample (representative)
* Large amounts of data collected
* Efficient as researcher does not have to be there whilst completed

Social desirability bias
If untruthful responses given reduces validity
Cannot be sure who completed it

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Open/Closed Questions

OPEN: Allows subject to freely express view/opinion in their own words

* Qualitative data
* High valitdity
Qualitative data - difficult to analyse
Low reliability

CLOSED: Respondents must choose an option for their response

* Quantitative data
* Standardised - High reliability
Low validity if chosen response not an option
Lacks detail

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Structured Interview

Interviewer sticks to a strict list of questions and uses a standardised procedure

* High reliability
* Easy to compare and analyse response
* High inter-rater reliability

Lacks validity as subject not free to expand on responses
Lacks detail 

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Unstructured Interview

Researcher has freedom to vary questions and go into more detail with responses

* High validity
* Produces more detailed information

Time consuming
Much of the information may not be relevant

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Likert Scale

List of attitudes about a statement and asked to indicate using a scale how strongly they agree or disagree.

* Quantitative data
* Extent of opinion measured

Social desirability bias
May misinterpret scale

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Shows a relationship between two co-variables

Positive correlation: As the values of one co-variable increase, the values of the other co-variable increase also (+1 coeffiecient)

Negative correlation:
As the values of one co-variable increase, the values of the other co-variable decrease. (-1 coefficient)

No correlation: There is no relationship between the two co-variables (0)

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Correlation Coeffiecient

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Descriptive Statistics

MEAN: Adding all values together and dividing by the number of values

* Most representative measure
May be influenced by extreme values

MEDIAN: The central number when values in chronological order

* uneffected by extreme values
Not all values represented

MODE: The most common value

* Can be used with any data type
Not useful with small data sets

RANGE: Difference between biggest and smallest value

*Easy to calculate
Doesn't indicate how widely or tightly spread a group of values are

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Standard Deviation

Calculates difference of a score from it's group mean

* More precise than range as all data accounted for
* Allows researcher to know how much scores vary amongst themselves

Difficult to calculate

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