Research methods - page 166-179

Definition of Experimental method

Involves the manipulation of an independent variable to measure the effect of the dependent variable. Experiments may be laboratory, field, natural or quasi.

Definition of an aim

A general statement of what the researcher intends to investigate; the purpose of the study

Definition of Hypothesis

A clear, precise, testable statement that states the relationship between the variables to be investigated. Stated at the outset of any study.

Definition of Directional Hypothesis

States the direction of the difference or relationship

Definition of Non-directional hypothesis

Does not state the direction of the difference or relationship

Definition of variables

Any ‘thing’ that can vary or change within an investigation. Variables are generally used in experiments to determine if changes in one thing result in changes to another.

Definition of an independent variable

Some aspect of the experimental situation that is manipulated by the researcher - or changes naturally - so the effect on the DV can be measured.

Definition of Operationalisation

Clearly defining variables in terms of how they can be measured

When should you use Directional hypothesis

Psychologists tend to use a directional hypothesis when findings of previous research studies suggest a particular outcome

When should you use a Non-Directional hypothesis

When there is no pervious research or findings from earlier studies are contradictory, they will instead decide to use a non-directional hypothesis.

how do you operationalise

make it obvious how they are being manipulated or measured. In particular, an operationalised DV will create quantitative data. For example: Not "intelligence" but "score on a IQ test"

Definition of Extraneous variables

Any variable, other than the independent variable, that may have an effect on the dependent variable if it is not controlled. Extraneous variables are essentially nuisance variables that do not vary systematically with the IV.

Definition of confounding variables

Any variable, other than the IV, that may have affected the DV so we cannot be sure of the true source of changes to the DV. Confounding variables vary systematically with the IV.

Definition of Demand characteristics

Any cue from the researcher or from the research situation that may be interpreted by participants as revealing the purpose of the investigation. This may lead to a participant changing their behaviour within the researcher situation.

Definition of Investigator effects

Any effect of the investigator’s behaviour (conscious or unconscious) on the research outcome (the DV). This may include everything from the design of the study to the selection of, and interaction with, participants during the research process.

Definition of Randomisation

The use of chance in order to control for the effects of bias when designing materials and deciding the order of conditions.

Definition for Standardisation

Using exactly the same formalised procedures and instructions for all participants in a research study.

Examples of Extraneous variables

Anything that is straightforward to control

e.g. participant age, lighting in the lab

Examples of confounding variables

personality is a confounding variable

Examples of demand characteristics

the participant looking for ways to work out the aim of the experiment

Examples of investigator effects

the investigator having an unconscious behaviour leading to the a change in the participants behaviour

Definitions of experimental design

The different ways in which the testing of participants can be organised

Definitions of Independent groups design

Participants are allocated to different groups where each group represents one experimental condition

definitions of repeated measures

All participants take part in all conditions of the experiment

Definitions of matched pairs design

Pairs of participants are first matched on some variables that may affect the DV. Then one member of the pair is assigned to condition A and the other to condition B.

Definition of random allocation

An attempt to control for participant variables in an independent groups design which ensures that each participant has the same chance of being in one condition as any other.

Definition of counterbalancing

An attempt to control for the effects of order in repeated measures design; half the participants experience the conditions in one order, and the other half in the opposite order.

pro and con for independent groups

+: Order effects are not a problem

-: Less economical than repeated measures

-: Twice as many participants needed to produce equivalent data to that collected in repeated measures

Pros and cons for repeated measures

+: Participant variables are controlled so fewer participants are needed

-: each participant has to do at least two tasks, this may be significant as they are more likely to work out the aim.

Pros and cons for matched pairs

+: only take part in one condition so order effects and demand characteristics is less of a problem

-: Time consuming

-: expensive

-: less economical

Definition of Labatory experiment

An experiment controlled environment within which the researcher manipulates the IV and records the effect on the DV, whilst maintaining strict control of extraneous variables

Definition of field experiment

An experiment that takes place in a natural setting within which the researcher but would have happened even if the researcher records the effect on a DV they have decided on

Definition of Natural experiment

An experiment where the change in the IV is not brought about by the researcher but would have happened even if the researcher had not been there.The researcher records the effect on a DV they have decided on.

Definition of a Quasi-experiment

A study that is almost an experiment but lacks key ingredients. The IV has not been determined by anyone (the researcher or any other person) - the ‘variables’ simply exist, such as being old or young. Strictly speaking this is not an experiment.

Pros and cons of a laboratory experiment

+: High control allows for because and effect realationships to be established

-:May lack ecological validity

Pros and cons of a field experiment

+:more likely to have ecological validity

-:less control, less random allocation

Pros and cons of a natural experiment

+: High ecological validit

What are the two types of external validity

ecological validity

population validity

What is ecological validity

may be able to generalise to real life

what is population validity

the extent to which you can generalise to the target population

Definitions of populations

A group of people who are the focus of the researchers interest, from which a smaller sample is drawn.

Definitions of Sample

A group of people who take part in a research investigation. The sample is drawn from a target population and is presumed to be representation of that population, I.e. it stands ‘fairly’ for the population being studied.

Definition of sampling techniques

The method used to select people from the population

Definition of Bias

In the context, when certain groups are over - or under - represented within the sample selected. For instance, there may be too many younger people or too many people of one ethnic origin in a sample. This limits the extent to which generalisations can be made to the target population.

Definition of Generalisation

The extent to which findings and conclusions from a particular investigation can be broadly applied to the population. This is possible if the sample of the participants is representative of the target population.

Definition of Target Population

Subset of the general population

Why is it difficult to get a representative target population?

The diverse nature of populations, therefore creating a degree of bias

What is the mneumonic to remember the sampling techniques

ROVSS

What are the five different types of sampling techniques

Random sample

Oppurtunity sample

Voulenteer sample

Systematic sample

Stratefied sample

What is a random sample

Where all members of the target population have an equal chance of being selected

How do you take a random sample

1. Obtain a list of all members in the target population

2. Asign all the names in the target population list a number

3. use a random number generator to generate participants

Pros of a random sample

• one of the least biased out of sample methods

• high internal validity

Cons of random sample

• difficult and time consuming to conduct

• A complete list of the target population would be challenging to obtain

• Not nescessarily representative

What is a systematic sample

When every nth member of the target population is selected

How to obtain a systematic sample

1. A sampling frame is produced, a list of people in target population organised into; alphabetical order

2. A sampling system is nominated, every nth person

3. The researcher then works through the sampling frame until the sample is complete

Pros of a systematic sample

• researcher has little influence over who is chosen

Cons of a systematic sample

• Time consuming

• Participants may refuse to take part resulting in a voulenteer sample

What is a stratified sample

Composition of the sample reflects the proportions of people in certain subgroups within the target population

How do you obtain a stratified sample

1. Identify the different strata that makes up the population

2. The proportions needed for the sample to be representative are worked out

3. The participants that make up each stratum are selected by using random sampling

Pros of a Stratified sample

• Representative sample

• Generalisation is possible

Cons of a Stratified sample

• Time consuming, because of the group sorting

What is an oppurtunity sample

researchers select anyone whos willing

How do you obtain an oppurtunity sample

Take a chance to ask whoever is around at the time of the study

Pros of an oppurtunity sample

• Convinient, because it is accessible

• Cheaper because it doesnt require any research

Cons of an oppurtunity sample

• Suffers from two forms of bias

• Unrepresentative of the target population

• cannot be generalised to the target population

• Researcher has complete control over selection of participants

• researcher bias

What is a voulenteer sample

Self selected

How do you obtain a voulenteer sample

Place an advert in a newspaper or noticeboard

or

voulenteers may raise their hands when a researcher asks

Definition of ethical issues

These arise when a conflict exists between the rights of participants in research studies and the goals of research to produce authentic valid and worth while data

Definition of the BPS code of ethics

A quasi legal document produced by the British Psychological Society that instructs pyschologists in the uk about what behaviour is and isnt acceptable when dealing with participants. The code is built around four major principle: respect, competence, responsibility and integrity.

When do ethical issues arise in psychology

When conflict or dilema exists between participants rights and researchers need to gain valuable and meaningful findings

What is the BPS code of conduct

• a set of ethical guidelines

• Researchers have a proffesional duty to follow the guidelines, if they didnt they may loose their jobs

Who implements the BPS code of conduct

The ethics committees in research institutions they use a cost benefit approach to work out whether particular research proposals are ethically acceptable

How do you give Informed consent

Informed consent means the participant has to be aware of the:

• aims of research.

• Their rights (right to withdraw)

• what their data will be used for

And then they can make an informed decision about whether they wish to partake

What is researchers issues with informed consent

Researchers see it as pointless as the participants behaviour will no longer be natural as they know the aim of the study

How can you deal with the issue of informed consent

• participants should be issued with a consent letter/form detailing all relevant Information that might affect their decision

• parental consent u16

What are the different types of consent

• Presumptive consent

• Prior general consent

• Retrospective consent

What is Presumptive consent

A similar group of people are asked if a study is acceptable if the group agrees the consent is presumed

What is prior general consent

Participants consent to a number of different studies including one involving deception this therefore means they consent to being decieved

What is retrospective consent

This is where the participant gives consent for their data to be used in the research once they've taken part and have been debriefed

What is Deception

Deliberately misleading or witholding information from participants at any stage of the investigation.

What is the issue around deception

If deception has occured participants are unable to have given their informed consent

When can deception be justified

If it does not because the participant undue distress

what is protection from harm

Participants should not be placed at more risks than they would be in their daily lives and should be protected from physical and pyschological harm

• embarrasment

• Inadequate

• stress/pressure

How do you deal with deception and protection from harm

• At the end of the study participants should be given a full debreif

• should be told what their data will be used for and given the right to withdraw

• been reassured behaviour was typical, or be provided counselling

What is the right of privacy

Participants have the right to control information about themselves

What is confidentaility

if privacy is invaded confidentiality should be protected

refers to our right enshrined in law under the data protection act to gave any personal data protected

institutions or geographical locations are not named

How do you deal with privacy and confidentaility

• dont record personal details

• refer to participants using numbers/initials when writing up the investigation

• during debreif they are told their data will be protected/not shared with other researchers

Definition of pilot study

A small scale version of an investigation that takes place before the real investigation is conducted. The aim is to check the procedures materials, measuring scales.

The aim is also to allow the researcher to make changes or modifications if nescessary.

What is a pilot study

A small scale trial run of the actual investigation.

Why would you do a pilot study

It gives the researcher a chance to identify any issues allowing them to modify the design or procedure, saves time and money in the long term

What is a single blind

The participant is not told the aim or any/if conditions on the experiment. Any information that might create expectations is not revealed until the end of the study

What is a double blind

The participant and the researcher are unaware of both the aims and the procedure

What is the control group

Used for the purpose of comparison

Why would you use a control group

If behaviour between control group and experimental group is different the researcher can then confidently say its a result of the independent variable (assuming all confounding variables remained constant)