Edexcel Cream booklet 2

Correlational research

Correlational research

Collects data to investigate the extent to which two variables are associated.If two variables are correlated, this means that they are associated or correlated in a way that shows a trend or systematic pattern linking them.

Co-variables

Are the two variables in a correlational study which have been measured

Correlational analysis

Is a data analysis technique that simply describes the relationships between two co-variables in statistical terms. There are two main types of correlational relationship - positive and negative correlations

A positive correlation

Is one where high values on one variable are associated with high values on the other variable OR low values on one variable are associated with low values on the other variables

A Negative Correlation

Is one where high values are associated with low values on the other variable

A correlation coefficient

Can be any number between -1 and +1. This number tells us the strength of the correlation and the direction

Good rule of thumb for Correlation coefficients

0.0 to 0.3 - weak 0.3 to 0.7 - moderate Above 0.7 - strong

Correlation Research Strengths

-allows identification of relationships between variables when when it is difficult for practical reasons or unethical to manipulate the variables the researcher is interested in

• starting point of future research

• is scientific tends to be objective

Correlation research Weaknesses

• there is little control over variables does not allow cause-and-effect links to be established -two co-variable may not be measured in valid manner -Correlations can be misused

Observation research

Focuses on the observation of a persons freely chosen behaviour. Does not have an IV that is controlled by the research we

Naturalistic research methods

Where behaviour is studied in its natural setting and the environment is left as it normally is without any manipulation by the researcher

Structured research methods

Observations where some of the variables including the environment are controlled. The observation may even be in a laboratory setting.These observations capture freely chosen behaviour but the situation may be set up.

Participant observations

When the observer becomes part of a group

Non-participant observations

Where the researcher is not involved in the action

Covert

When the participants do not know they are being observed

Overt

When the observer is know to be present by those observed

Collecting quantitative data

Using categorised recording systems

Collecting qualitative data

Using descriptive note taking

Evaluation of Naturalistic Observations

• setting is natural so observers remain covert meaning ecological validity high meaning it is more generalisable -remaining hidden may difficult people may become aware this is a threat to validity

Ecological validity

Refers to the extent to which research finding can be generalised to a different environment.

Structured Observations Evaluation

-more control over the environment leads to easier replication -Ecological validity tends to be lower due to lab based environment

Participant Observations Evaluations

-better understanding of events -High ecological validity -ethical issues raised due to undisclosed observers

Non-participant observation evaluation

-accuracy of the observations and amount of data collected higher -Objectivity higher as observer as not stake in activities observed -observer have little understanding on what is going on

Covert Observation evaluation

• advantage - avoid demand characteristics

• disadvantages - no right to withdraw ethical issues

Overt observations evaluations

• advantage - know more about participants

• disadvantages - may lead to Hawthorne effect

Continuous observations

The observer records every instance of behaviour

• may have too much data to record

Time sampling

Recording target behaviour for set lengths of time set intervals

Event sampling

Recording certain behaviour every time it occurs in target individual throughout observation period

Content analysis

Is a research technique for the systematic quantitative description of the content written spoken or visual human communications.

The media

Any medium that can be recorded and reviewed -print media -visual media -visual artistic production

Primary research data

New information that has been generated as part of a research product

• open-ended questions -notes made by an observer

Research Question and hypothesis

Shapes the way the research is done and helps in choosing appropriate materials and coding units

Sampling

Material of interest defined How much of available information will be analysed

Coding units

Analysed to best answer their research question -word -theme -item -time and space

Pilot studies

Must become familiar with materially likely to be encountered and improve the system.

Collecting the data

Recording the number of occurrences in a particular coding category

Content Analysis

Strengths -summarising extensive qualitative data into quantitive data

• external validity can be high

• ethical issues not a major problem Weaknesses -cannot show cause and effect -subjectivity can be high -can be unrepresentative

fMRI scans

Produce images of brain activity and functioning by showing tiny metabolic changes that take place in an active part of the brain

How fMRI works

Measuring brain activity it works by detecting the changes in blood oxygenation and flow that occur in response to neural activity

Evaluation of the use of fMRI scanning

-non-invasive -cannot look at the activity of actual receptors of neurotransmitters

CAT scans

Only gives limited information as fine detail within the image may be invisible

How CAT works

-large number of detectors -gives composite detailed 3D image

Evaluation of CAT scanning

-less harmful than PET scanning

• very detailed images -slight chance of cancer from excessive exposure to radiation

PET scanning

Uses small amounts of radioactive material called radio tracers changes in the Braun at cellular level

How PET works

Radio tracer is injected into the body accumulates where glucose is being used.record emission of energy draws to the active area

Evaluation of PET scanning

-measures important functions -they are reliable can be replicated exactly -it may be open to bias -radiation exposure to patient